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<front>
<journal-meta>
<journal-id journal-id-type="nlm-ta">PLoS ONE</journal-id>
<journal-id journal-id-type="publisher-id">plos</journal-id>
<journal-id journal-id-type="pmc">plosone</journal-id>
<journal-title-group>
<journal-title>PLOS ONE</journal-title>
</journal-title-group>
<issn pub-type="epub">1932-6203</issn>
<publisher>
<publisher-name>Public Library of Science</publisher-name>
<publisher-loc>San Francisco, CA USA</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.1371/journal.pone.0300188</article-id>
<article-id pub-id-type="publisher-id">PONE-D-23-23392</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Research Article</subject>
</subj-group>
<subj-group subj-group-type="Discipline-v3">
<subject>Medicine and health sciences</subject><subj-group><subject>Public and occupational health</subject><subj-group><subject>Physical activity</subject></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>Social sciences</subject><subj-group><subject>Sociology</subject><subj-group><subject>Human families</subject></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>People and places</subject><subj-group><subject>Population groupings</subject><subj-group><subject>Age groups</subject><subj-group><subject>Children</subject><subj-group><subject>Adolescents</subject></subj-group></subj-group></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>People and places</subject><subj-group><subject>Population groupings</subject><subj-group><subject>Families</subject><subj-group><subject>Children</subject><subj-group><subject>Adolescents</subject></subj-group></subj-group></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>Biology and life sciences</subject><subj-group><subject>Psychology</subject><subj-group><subject>Behavior</subject><subj-group><subject>Recreation</subject><subj-group><subject>Sports</subject></subj-group></subj-group></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>Social sciences</subject><subj-group><subject>Psychology</subject><subj-group><subject>Behavior</subject><subj-group><subject>Recreation</subject><subj-group><subject>Sports</subject></subj-group></subj-group></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>Biology and life sciences</subject><subj-group><subject>Sports science</subject><subj-group><subject>Sports</subject></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>People and places</subject><subj-group><subject>Geographical locations</subject><subj-group><subject>Europe</subject></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>Social sciences</subject><subj-group><subject>Sociology</subject><subj-group><subject>Education</subject><subj-group><subject>Schools</subject></subj-group></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>Medicine and health sciences</subject><subj-group><subject>Public and occupational health</subject><subj-group><subject>Behavioral and social aspects of health</subject></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>Medicine and health sciences</subject><subj-group><subject>Health care</subject><subj-group><subject>Socioeconomic aspects of health</subject></subj-group></subj-group></subj-group><subj-group subj-group-type="Discipline-v3">
<subject>Medicine and health sciences</subject><subj-group><subject>Public and occupational health</subject><subj-group><subject>Socioeconomic aspects of health</subject></subj-group></subj-group></subj-group></article-categories>
<title-group>
<article-title>Family structure and the association with physical activity—Findings from 40 countries participating in the Health Behaviour in School-aged Children (HBSC) study</article-title>
<alt-title alt-title-type="running-head">Family structure and physical activity findings from the health behaviour in school-aged children study</alt-title>
</title-group>
<contrib-group>
<contrib contrib-type="author" corresp="yes" xlink:type="simple">
<name name-style="western">
<surname>Haug</surname>
<given-names>Ellen</given-names>
</name>
<role content-type="http://credit.niso.org/contributor-roles/conceptualization/">Conceptualization</role>
<role content-type="http://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
<role content-type="http://credit.niso.org/contributor-roles/investigation/">Investigation</role>
<role content-type="http://credit.niso.org/contributor-roles/methodology/">Methodology</role>
<role content-type="http://credit.niso.org/contributor-roles/writing-original-draft/">Writing – original draft</role>
<xref ref-type="aff" rid="aff001"><sup>1</sup></xref>
<xref ref-type="aff" rid="aff002"><sup>2</sup></xref>
<xref ref-type="corresp" rid="cor001">*</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple">
<name name-style="western">
<surname>Smith</surname>
<given-names>Otto Robert Frans</given-names>
</name>
<role content-type="http://credit.niso.org/contributor-roles/conceptualization/">Conceptualization</role>
<role content-type="http://credit.niso.org/contributor-roles/formal-analysis/">Formal analysis</role>
<role content-type="http://credit.niso.org/contributor-roles/writing-review-editing/">Writing – review &amp; editing</role>
<xref ref-type="aff" rid="aff002"><sup>2</sup></xref>
<xref ref-type="aff" rid="aff003"><sup>3</sup></xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple">
<name name-style="western">
<surname>Ng</surname>
<given-names>Kwok</given-names>
</name>
<role content-type="http://credit.niso.org/contributor-roles/writing-review-editing/">Writing – review &amp; editing</role>
<xref ref-type="aff" rid="aff004"><sup>4</sup></xref>
<xref ref-type="aff" rid="aff005"><sup>5</sup></xref>
<xref ref-type="aff" rid="aff006"><sup>6</sup></xref>
<xref ref-type="aff" rid="aff007"><sup>7</sup></xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple">
<name name-style="western">
<surname>Samdal</surname>
<given-names>Oddrun</given-names>
</name>
<role content-type="http://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
<role content-type="http://credit.niso.org/contributor-roles/writing-review-editing/">Writing – review &amp; editing</role>
<xref ref-type="aff" rid="aff001"><sup>1</sup></xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple">
<name name-style="western">
<surname>Marques</surname>
<given-names>Adilson</given-names>
</name>
<role content-type="http://credit.niso.org/contributor-roles/writing-review-editing/">Writing – review &amp; editing</role>
<xref ref-type="aff" rid="aff008"><sup>8</sup></xref>
<xref ref-type="aff" rid="aff009"><sup>9</sup></xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple">
<contrib-id authenticated="true" contrib-id-type="orcid">https://orcid.org/0000-0001-8235-8775</contrib-id>
<name name-style="western">
<surname>Borraccino</surname>
<given-names>Alberto</given-names>
</name>
<role content-type="http://credit.niso.org/contributor-roles/writing-review-editing/">Writing – review &amp; editing</role>
<xref ref-type="aff" rid="aff010"><sup>10</sup></xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple">
<contrib-id authenticated="true" contrib-id-type="orcid">https://orcid.org/0000-0002-9101-0583</contrib-id>
<name name-style="western">
<surname>Kopcakova</surname>
<given-names>Jaroslava</given-names>
</name>
<role content-type="http://credit.niso.org/contributor-roles/writing-review-editing/">Writing – review &amp; editing</role>
<xref ref-type="aff" rid="aff011"><sup>11</sup></xref>
<xref ref-type="aff" rid="aff012"><sup>12</sup></xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple">
<name name-style="western">
<surname>Oja</surname>
<given-names>Leila</given-names>
</name>
<role content-type="http://credit.niso.org/contributor-roles/writing-review-editing/">Writing – review &amp; editing</role>
<xref ref-type="aff" rid="aff013"><sup>13</sup></xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple">
<name name-style="western">
<surname>Fismen</surname>
<given-names>Anne-Siri</given-names>
</name>
<role content-type="http://credit.niso.org/contributor-roles/conceptualization/">Conceptualization</role>
<role content-type="http://credit.niso.org/contributor-roles/writing-review-editing/">Writing – review &amp; editing</role>
<xref ref-type="aff" rid="aff014"><sup>14</sup></xref>
</contrib>
</contrib-group>
<aff id="aff001"><label>1</label> <addr-line>Department of Health Promotion and Development, University of Bergen, Bergen, Norway</addr-line></aff>
<aff id="aff002"><label>2</label> <addr-line>Department of Teacher Education, NLA University College, Bergen, Norway</addr-line></aff>
<aff id="aff003"><label>3</label> <addr-line>Department of Health Promotion, Norwegian Institute of Public Health, Bergen, Norway</addr-line></aff>
<aff id="aff004"><label>4</label> <addr-line>Faculty of Education, University of Turku, Turku, Finland</addr-line></aff>
<aff id="aff005"><label>5</label> <addr-line>Physical Activity for Health Research Centre, Department of Physical Education and Sport Sciences, Health Research Institute, University of Limerick, Limerick, Ireland</addr-line></aff>
<aff id="aff006"><label>6</label> <addr-line>School of Educational Sciences and Psychology, University of Eastern Finland, Finland</addr-line></aff>
<aff id="aff007"><label>7</label> <addr-line>Faculty of Sport and Health Sciences, University of Jyvaskyla, Jyvaskyla, Finland</addr-line></aff>
<aff id="aff008"><label>8</label> <addr-line>CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal</addr-line></aff>
<aff id="aff009"><label>9</label> <addr-line>ISAMB, Universidade de Lisboa, Lisbon, Portugal</addr-line></aff>
<aff id="aff010"><label>10</label> <addr-line>Department of Clinical and Biological Sciences Public Health and Paediatrics, University of Torino, Orbassano (TO), Italy</addr-line></aff>
<aff id="aff011"><label>11</label> <addr-line>Department of Health Psychology and Research Methodology, Faculty of Medicine, P.J. Safarik University in Kosice, Kosice, Slovakia</addr-line></aff>
<aff id="aff012"><label>12</label> <addr-line>Olomouc University Social Health Institute, Palacky University Olomouc, Olomouc, Czech Republic</addr-line></aff>
<aff id="aff013"><label>13</label> <addr-line>National Institute for Health Development, Estonia</addr-line></aff>
<aff id="aff014"><label>14</label> <addr-line>Faculty of Health and Social Sciences, Western Norway University of Applied Sciences, Inndalsveien, Bergen, Norway</addr-line></aff>
<contrib-group>
<contrib contrib-type="editor" xlink:type="simple">
<name name-style="western">
<surname>Jaafar</surname>
<given-names>Zulkarnain</given-names>
</name>
<role>Editor</role>
<xref ref-type="aff" rid="edit1"/>
</contrib>
</contrib-group>
<aff id="edit1"><addr-line>Universiti Malaya, MALAYSIA</addr-line></aff>
<author-notes>
<fn fn-type="conflict" id="coi001">
<p>The authors have declared that no competing interests exist.</p>
</fn>
<corresp id="cor001">* E-mail: <email xlink:type="simple">ellen.haug@uib.no</email></corresp>
</author-notes>
<pub-date pub-type="epub">
<day>17</day>
<month>4</month>
<year>2024</year>
</pub-date>
<pub-date pub-type="collection">
<year>2024</year>
</pub-date>
<volume>19</volume>
<issue>4</issue>
<elocation-id>e0300188</elocation-id>
<history>
<date date-type="received">
<day>5</day>
<month>9</month>
<year>2023</year>
</date>
<date date-type="accepted">
<day>23</day>
<month>2</month>
<year>2024</year>
</date>
</history>
<permissions>
<copyright-year>2024</copyright-year>
<copyright-holder>Haug et al</copyright-holder>
<license xlink:href="http://creativecommons.org/licenses/by/4.0/" xlink:type="simple">
<license-p>This is an open access article distributed under the terms of the <ext-link ext-link-type="uri" xlink:href="http://creativecommons.org/licenses/by/4.0/" xlink:type="simple">Creative Commons Attribution License</ext-link>, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.</license-p>
</license>
</permissions>
<self-uri content-type="pdf" xlink:href="info:doi/10.1371/journal.pone.0300188"/>
<abstract>
<sec id="sec001">
<title>Background</title>
<p>The family has been acknowledged as central to developing physical activity (PA) beliefs and behaviours. However, increased diversity in family structures has developed over the last decades. This study examines the association between family structure and PA among adolescents and cross-national variations in the associations.</p>
</sec>
<sec id="sec002">
<title>Methods</title>
<p>The data are from the 2013/14 Health Behaviours in School-Aged Children study, involving nationally representative samples of 11-, 13- and 15-year-olds (n = 211,798) from 40 countries. Multilevel Poisson regression analysis was used to examine the associations between family structure and moderate to vigorous physical activity (MVPA) and vigorous physical activity (VPA) by age, gender, socioeconomic status (SES), and geographic region.</p>
</sec>
<sec id="sec003">
<title>Results</title>
<p>Living with one versus two parents was associated with a reduced likelihood of daily 60 min MVPA for boys (IRR = 0.96, 95% CI: 0.92, 0.99) and ≥ 4 times/week VPA (IRR 0.93, 95% CI: 0.91, 0.95). This impact on MVPA differed across individual-level SES (high SES; IRR = 0.92, (p &lt;0.05), low SES; IRR = 1.04, (ns)), and was for VPA only significant for those with siblings (IRR = 0.93, 95% CI: 0.91, 0.96). Cross-country variations in the association between living with one versus two parents were observed, most pronounced for VPA. These differences varied by region, primarily explained by country-level SES differences between regions. The likelihood of daily 60 min MVPA also increased with siblings in the main house (IRR 1.11, 95% CI: 1.07, 1.14), and ≥ 4 times/week VPA decreased with grandparents in the main house (IRR 0.91, 95% CI: 0.89,0.94).</p>
</sec>
<sec id="sec004">
<title>Conclusions</title>
<p>Family structure correlated with PA, but cross-country differences exist. The findings are relevant for the development of policies and programs to facilitate PA, especially in countries where living with one versus two parents was unfavourable. Additional country-specific research is needed to identify challenges for engaging in PA related to family structure.</p>
</sec>
</abstract>
<funding-group>
<award-group id="award001">
<funding-source>
<institution-wrap>
<institution-id institution-id-type="funder-id">http://dx.doi.org/10.13039/501100005357</institution-id>
<institution>Agentúra na Podporu Výskumu a Vývoja</institution>
</institution-wrap>
</funding-source>
<award-id>APVV-22-0078</award-id>
<principal-award-recipient>
<contrib-id authenticated="true" contrib-id-type="orcid">https://orcid.org/0000-0002-9101-0583</contrib-id>
<name name-style="western">
<surname>Kopcakova</surname>
<given-names>Jaroslava</given-names>
</name>
</principal-award-recipient>
</award-group>
<funding-statement>The Slovak HBSC data collection and JK was supported by the Slovak Research and Development Support Agency under Contract no. APVV-22-0078. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.</funding-statement>
</funding-group>
<counts>
<fig-count count="4"/>
<table-count count="3"/>
<page-count count="20"/>
</counts>
<custom-meta-group>
<custom-meta id="data-availability">
<meta-name>Data Availability</meta-name>
<meta-value>Data are available from the HBSC Institutional Data access (<ext-link ext-link-type="uri" xlink:href="http://www.hbscdata.uib.no/" xlink:type="simple">www.hbscdata.uib.no</ext-link>) for external researchers who meet the criteria for access to the data.</meta-value>
</custom-meta>
</custom-meta-group>
</article-meta>
</front>
<body>
<sec id="sec005" sec-type="intro">
<title>Introduction</title>
<p>Being physically active is linked to numerous health benefits, both from a medical and psychological perspective. Children and adolescents who regularly practice physical activity (PA) have a better lipid profile, less body fat, better levels of physical fitness, and a lower risk of having metabolic syndrome [<xref ref-type="bibr" rid="pone.0300188.ref001">1</xref>, <xref ref-type="bibr" rid="pone.0300188.ref002">2</xref>]. Adolescents who are more physically active also have fewer complaints of psychosomatic symptoms [<xref ref-type="bibr" rid="pone.0300188.ref003">3</xref>] and are less likely to experience depression [<xref ref-type="bibr" rid="pone.0300188.ref001">1</xref>, <xref ref-type="bibr" rid="pone.0300188.ref004">4</xref>], suicidal ideation [<xref ref-type="bibr" rid="pone.0300188.ref005">5</xref>], and other mental health problems [<xref ref-type="bibr" rid="pone.0300188.ref006">6</xref>]. In addition, adolescents who practice more PA are likely to have better academic performance [<xref ref-type="bibr" rid="pone.0300188.ref006">6</xref>, <xref ref-type="bibr" rid="pone.0300188.ref007">7</xref>]. However, despite the benefits of PA, many children and adolescents don’t comply with governmental recommendations and the PA guidelines from the World Health Organization (WHO) [<xref ref-type="bibr" rid="pone.0300188.ref008">8</xref>, <xref ref-type="bibr" rid="pone.0300188.ref009">9</xref>]. In Europe, large within and between-country differences in PA levels are typically observed [<xref ref-type="bibr" rid="pone.0300188.ref008">8</xref>]. As low levels of PA during adolescence compromise present and future health, factors that may influence adolescents’ PA behaviour must be identified to inform the development of evidence-based strategies and interventions [<xref ref-type="bibr" rid="pone.0300188.ref010">10</xref>].</p>
<p>Socio-ecological models emphasise that PA is a complex behaviour determined by a broad range of factors at multiple levels [<xref ref-type="bibr" rid="pone.0300188.ref011">11</xref>]. The family typically represents the earliest setting for PA experiences and has been acknowledged as central to developing PA beliefs and behaviours [<xref ref-type="bibr" rid="pone.0300188.ref012">12</xref>]. Parental influences have been of particular interest. Parents can either directly or indirectly affect adolescents’ PA with supportive actions relating to encouragement, involvement, transport facilitation and economic aid [<xref ref-type="bibr" rid="pone.0300188.ref013">13</xref>, <xref ref-type="bibr" rid="pone.0300188.ref014">14</xref>] by fostering a motivational climate [<xref ref-type="bibr" rid="pone.0300188.ref015">15</xref>, <xref ref-type="bibr" rid="pone.0300188.ref016">16</xref>] and as role models for PA [<xref ref-type="bibr" rid="pone.0300188.ref017">17</xref>, <xref ref-type="bibr" rid="pone.0300188.ref018">18</xref>].</p>
<p>However, adolescents in Westernised societies increasingly live in various family unit structures. Over the past decades, more children and adolescents are growing up in one-parent families, in joint custody or reconstructed families consisting of a parent and a stepparent [<xref ref-type="bibr" rid="pone.0300188.ref019">19</xref>–<xref ref-type="bibr" rid="pone.0300188.ref021">21</xref>]. This trend of increased diversity in family structures has led to an interest in how the family in which children grow up may affect adolescents’ health and health behaviours. In general, the literature suggests that living in households other than a traditional family constituted by both parents is less favourable for various health behaviours [<xref ref-type="bibr" rid="pone.0300188.ref022">22</xref>–<xref ref-type="bibr" rid="pone.0300188.ref025">25</xref>] and also for weight status [<xref ref-type="bibr" rid="pone.0300188.ref026">26</xref>]. Research on the relationship between family structure and adolescent PA behaviours has so far produced mixed results. Some studies report no differences in measures of PA between children from one versus two-parent families [<xref ref-type="bibr" rid="pone.0300188.ref027">27</xref>–<xref ref-type="bibr" rid="pone.0300188.ref031">31</xref>]. However, most studies find positive associations with two-parent families [<xref ref-type="bibr" rid="pone.0300188.ref032">32</xref>–<xref ref-type="bibr" rid="pone.0300188.ref038">38</xref>]. In contrast, fewer studies report positive associations between one-parent [<xref ref-type="bibr" rid="pone.0300188.ref039">39</xref>–<xref ref-type="bibr" rid="pone.0300188.ref042">42</xref>] or stepparent families [<xref ref-type="bibr" rid="pone.0300188.ref041">41</xref>]. However, a better understanding of the association between family structure and PA from the European context and with a cross-national perspective is needed.</p>
<p>In most previous studies, family structure has been categorised as single- vs dual-parent households, ignoring the possible impact of other family structures, such as living with a stepparent in the house, having siblings or living with grandparents. For instance, siblings are assumed to contribute to both positive and negative experiences in PA and sports through encouragement, support, jealousy, and rivalry, and with varied experiences of PA, depending on sex composition [<xref ref-type="bibr" rid="pone.0300188.ref012">12</xref>]. Thus, a broader examination of family structures can provide a more nuanced understanding of family composition as a contextual correlate of young people’s PA.</p>
<p>Understanding why disparities exist according to family structure has become increasingly important. It has been suggested that family structure is related to socioeconomic status (SES) [<xref ref-type="bibr" rid="pone.0300188.ref043">43</xref>] and that living with one (versus two parents) may be associated with socioeconomic disadvantages [<xref ref-type="bibr" rid="pone.0300188.ref044">44</xref>]. This underlines the importance of considering family structure in light of social inequalities when addressing adolescents’ health and health behaviours. From a socio-ecological perspective [<xref ref-type="bibr" rid="pone.0300188.ref011">11</xref>], the current study will add to the existing literature by providing an extensive cross-country examination of the relationship between family structure and PA, which opens up a broader understanding of how environmental factors, policies, and the organisation of adolescent sport, may interplay with an individual’s PA across family structures.</p>
<p>Hence, the objective of the present study was to examine associations between various family structures and moderate to vigorous physical activity (MVPA) as well as vigorous physical activity (VPA) among adolescents across the WHO European region and Canada participating in the “Health Behaviour in School-aged Children’’ study. A WHO Cross-national study” (HBSC). We also examined the cross-country variations in the associations between living with one versus two parents in PA.</p>
</sec>
<sec id="sec006" sec-type="materials|methods">
<title>Materials and methods</title>
<sec id="sec007">
<title>Study design and data collection</title>
<p>The present study is based on nationally representative data from adolescents aged 11, 13, and 15 years from 40 countries participating in the HBSC survey in 2013/2014. The HBSC study aims to enhance the understanding of young people’s health behaviours in their social settings. The students answered a standardised questionnaire at school after receiving instructions from their teacher. Oral and written information on the confidentiality of their responses was provided, and participation was voluntary. Most countries used school class as the primary sampling unit (some countries used schools as the sampling unit). Schools/classes that declined to participate and students absent on the day the survey was carried out were the two main sources of non-response and were not followed up. In most countries included, response rates at the school, class, or student level exceeded 80% [<xref ref-type="bibr" rid="pone.0300188.ref045">45</xref>].</p>
<p>This study was conducted according to the guidelines in the Declaration of Helsinki. The HBSC study was approved by the Regional Committees for Medical and Health Research Ethics that approved this study in Norway, with additional approvals at the country level based on national requirements for this type of study (please see HBSC_ethics_2014_supplementary file for details).” Parental written or passive informed consent to participate was obtained in accordance with requirements from the national/local ethical boards. The HBSC Data Management Centre checked the quality of the data collected, performed appropriate cleaning, and merged national data sets into an international data file. The methodology for data collection is described in the HBSC protocol [<xref ref-type="bibr" rid="pone.0300188.ref046">46</xref>], which prescribes consistency in sampling plans, survey instruments and data collection. Detailed information about the study is available at <ext-link ext-link-type="uri" xlink:href="http://www.hbsc.org/" xlink:type="simple">http://www.hbsc.org/</ext-link>.</p>
</sec>
<sec id="sec008">
<title>Measures</title>
<sec id="sec009">
<title>Demographic</title>
<p>Gender was measured as either boy or girl. The participant also reported the month and year of birth, which was then calculated based on the survey completion time. After rounding to the nearest age group, they were subsequently grouped as 11-, 13- and 15-year-olds.</p>
</sec>
<sec id="sec010">
<title>Family structure</title>
<p>Family structure was measured by a single item: “Please answer this first question for the home where you live all or most of the time and tick the people who live there”. The response categories were mother, father, stepmother (or father’s partner), stepfather (or mother’s partner), grandfather, grandmother, foster home, and others. The data were coded into three categories: one parent in the main home, both parents in the main home, and no parents in the main home. Participants in the latter category (1.8%) were excluded from all analyses. Separate binary variables were derived for stepparent in the main home (yes/no) and grandparent(s) in the main home (yes/no) and were included as covariates. Having siblings in the main home (yes/no) was derived from two items referring to where the respondent lived all or most of the time: “Please indicate how many brothers and sisters live here (including half, step or foster brothers and sisters)” (How many brothers?, How many sisters?).</p>
</sec>
<sec id="sec011">
<title>Moderate to vigorous physical activity</title>
<p>MVPA was measured with a single item introduced by the following definition of PA intensity levels: “Physical activity is any activity that increases your heart rate and makes you get out of breath some of the time. Examples, including local examples, were provided with the statement, “Physical activity can be done in sports, school activities, playing with friends, or walking to school” before asking the following question, “Over the past 7 days, on how many days were you physically active for a total of at least 60 minutes per day?”. Please add up all the time you spent in physical activity each day” with possible responses ranging from 0 to 7 days [<xref ref-type="bibr" rid="pone.0300188.ref047">47</xref>]. The item has reasonable validity, moderate reliability [<xref ref-type="bibr" rid="pone.0300188.ref048">48</xref>, <xref ref-type="bibr" rid="pone.0300188.ref049">49</xref>], and acceptable correlation with accelerometer measures [<xref ref-type="bibr" rid="pone.0300188.ref050">50</xref>, <xref ref-type="bibr" rid="pone.0300188.ref051">51</xref>]. To reflect the daily PA recommendations, we dichotomised the item with a cut-off point for daily MVPA of at least 60 min daily.</p>
</sec>
<sec id="sec012">
<title>Vigorous physical activity</title>
<p>VPA was measured by asking the respondents the following question: ‘‘Outside school hours: How often do you usually exercise in your free time so much that you get out of breath or sweat?” with the possible responses: Every day/4 to 6 times a week/2 to 3 times a week/Once a week/Once a month/Less than once a month/Never. To reflect international recommendations, the cut-off for participating in VPA regularly was set to four or more times a week following the international HBSC report [<xref ref-type="bibr" rid="pone.0300188.ref008">8</xref>]. The item has good reliability [<xref ref-type="bibr" rid="pone.0300188.ref052">52</xref>, <xref ref-type="bibr" rid="pone.0300188.ref053">53</xref>]. Validity was fair when correlated with maximal oxygen consumption [<xref ref-type="bibr" rid="pone.0300188.ref053">53</xref>] and with accelerometer measurement [<xref ref-type="bibr" rid="pone.0300188.ref050">50</xref>].</p>
</sec>
<sec id="sec013">
<title>Socioeconomic status</title>
<p>SES was assessed using the family affluence scale (FAS) [<xref ref-type="bibr" rid="pone.0300188.ref054">54</xref>]. FAS is a measure of material affluence derived from the characteristics of the family’s household and consists of six items (family car, number of computers, own bedroom, family holidays, number of bathrooms, dishwasher in home). FAS is considered a valid SES indicator [<xref ref-type="bibr" rid="pone.0300188.ref055">55</xref>] and also for cross-national comparison [<xref ref-type="bibr" rid="pone.0300188.ref056">56</xref>]. Each student was assigned an individual FAS score (individual-level SES) ranging from 0 (low) to 13 (high), and each country had a mean FAS score (country-level SES), which was calculated from individual-level FAS within the respective country. The SES indicators were included in the analysis.</p>
</sec>
<sec id="sec014">
<title>Country classifications</title>
<p>European subregions were coded according to the EuroVoc classification [<xref ref-type="bibr" rid="pone.0300188.ref057">57</xref>], encompassing four separate regions. Canada was included in the Western European group. Israel was included in the Southern European group.</p>
</sec>
</sec>
<sec id="sec015">
<title>Statistics</title>
<p>Multilevel Poisson regression analysis was used to examine the associations between family structure and measures of MVPA and VPA. Level-1 units were students, and level-2 units were classes. All countries were pooled together for analysis, and the country variable was modelled as a fixed effect [<xref ref-type="bibr" rid="pone.0300188.ref058">58</xref>]. We started with a simple random intercept model with family structure as the only covariate (model 1). In the next steps, all level-1 predictors (gender, age, individual-level SES, stepparent in main home, grandparent(s) in main home, siblings in main home, and country) were first added as main effects (model 2), followed by a model that included the 2-way interactions of the model 2 predictors with family structure. Non-significant interactions based on the Wald-test were deleted and the model was re-run with significant interactions only (model 3). To examine whether potential country variations in the association between family structure on the one hand and MVPA and VPA, on the other hand, could be explained by geographical region or country-level family affluence, the country-by-family structure interaction of model 3 was replaced by the two cross-level interactions that included the mentioned country-level variables and family structure (model 4a: geographical region; model 4b: geographical region and country-level family affluence). Individual family affluence (individual-level SES) was group-mean centred and used as a level-1 predictor, whereas country-level family affluence (country-level SES) was grand-mean centred. Categorical variables were left uncentered. All analyses were conducted in STATA v.15.</p>
</sec>
</sec>
<sec id="sec016" sec-type="results">
<title>Results</title>
<p>The current sample included 211,798 adolescents (49.2% boys) from 40 countries. Boys were underrepresented in the Irish (38.9%) and the Russian (43.8%) samples. <xref ref-type="table" rid="pone.0300188.t001">Table 1</xref> reports cross-country heterogeneity in family structure, individual-level SES, country-level SES and proportion of adolescents reporting daily 60 min MVPA and ≥ 4 times/week VPA. The percentages of adolescents living with one parent in the main home ranged from 6.4 in Albania to 38.3 in Greenland. In the total sample, 23.2% lived with one parent, 8.7% with a stepparent in addition to one of their parents, and 15.6% with grandparents in the main home. Moreover, 83.2% had siblings in the main home. In total, 20.4% reported daily 60 min MVPA, ranging from 10.3% in Italy to 28.6% in Bulgaria. In comparison, 25.4% participated ≥ 4 times/week VPA in their free time, ranging from 9.4% in Armenia to 46.4% in Norway. The country-level mean SES (FAS) varied from 4.9 (Albania) to 9.9 (Luxemburg).</p>
<table-wrap id="pone.0300188.t001" position="float">
<object-id pub-id-type="doi">10.1371/journal.pone.0300188.t001</object-id>
<label>Table 1</label> <caption><title>Characteristics of the study population (n = 215 509 students)<xref ref-type="table-fn" rid="t001fn001">*</xref>.</title></caption>
<alternatives>
<graphic id="pone.0300188.t001g" mimetype="image" position="float" xlink:href="info:doi/10.1371/journal.pone.0300188.t001" xlink:type="simple"/>
<table>
<colgroup>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
</colgroup>
<thead>
<tr>
<th align="left"/>
<th align="center">N</th>
<th align="center">Boys (%)</th>
<th align="center">13 yr(%)</th>
<th align="left">15 yr (%)</th>
<th align="left">Country Level SES</th>
<th align="left">One parent in the main home (%)</th>
<th align="left">Stepparent in the main home (%)</th>
<th align="left">Grandparent (s) in the main home (%)</th>
<th align="left">Sibling (s) in the main home (%)</th>
<th align="left">Daily 60 MIN MVPA (%)</th>
<th align="left">≥ 4 times/week VPA (%)</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left"><bold>Western Europe</bold></td>
<td align="left"/>
<td align="left"/>
<td align="center"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
</tr>
<tr>
<td align="left">Austria</td>
<td align="center">3416</td>
<td align="center">46.5</td>
<td align="char" char=".">31.7</td>
<td align="char" char=".">37.0</td>
<td align="char" char=".">9.0</td>
<td align="char" char=".">22.5</td>
<td align="char" char=".">7.6</td>
<td align="char" char=".">20.0</td>
<td align="char" char=".">89.2</td>
<td align="char" char=".">19.9</td>
<td align="char" char=".">33.5</td>
</tr>
<tr>
<td align="left">Belgium (French)</td>
<td align="center">5814</td>
<td align="center">49.7</td>
<td align="char" char=".">33.7</td>
<td align="char" char=".">32.7</td>
<td align="char" char=".">8.5</td>
<td align="char" char=".">26.9</td>
<td align="char" char=".">16.9</td>
<td align="char" char=".">6.3</td>
<td align="char" char=".">91.9</td>
<td align="char" char=".">17.9</td>
<td align="char" char=".">31.3</td>
</tr>
<tr>
<td align="left">Belgium(Flemish)</td>
<td align="center">4359</td>
<td align="center">54.9</td>
<td align="char" char=".">27.0</td>
<td align="char" char=".">39.5</td>
<td align="char" char=".">8.9</td>
<td align="char" char=".">23.1</td>
<td align="char" char=".">14.5</td>
<td align="char" char=".">14.2</td>
<td align="char" char=".">89.8</td>
<td align="char" char=".">15.2</td>
<td align="char" char=".">38.6</td>
</tr>
<tr>
<td align="left">Canada</td>
<td align="center">12530</td>
<td align="center">49.5</td>
<td align="char" char=".">37.3</td>
<td align="char" char=".">38.5</td>
<td align="char" char=".">8.7</td>
<td align="char" char=".">28.5</td>
<td align="char" char=".">11.2</td>
<td align="char" char=".">6.1</td>
<td align="char" char=".">86.0</td>
<td align="char" char=".">25.0</td>
<td align="char" char=".">34.1</td>
</tr>
<tr>
<td align="left">Germany</td>
<td align="center">5893</td>
<td align="center">50.9</td>
<td align="char" char=".">35.1</td>
<td align="char" char=".">35.6</td>
<td align="char" char=".">8.9</td>
<td align="char" char=".">23.4</td>
<td align="char" char=".">9.9</td>
<td align="char" char=".">14.4</td>
<td align="char" char=".">86.0</td>
<td align="char" char=".">15.4</td>
<td align="char" char=".">32.9</td>
</tr>
<tr>
<td align="left">England</td>
<td align="center">5264</td>
<td align="center">51.9</td>
<td align="char" char=".">29.9</td>
<td align="char" char=".">30.4</td>
<td align="char" char=".">8.8</td>
<td align="char" char=".">27.6</td>
<td align="char" char=".">11.3</td>
<td align="char" char=".">8.1</td>
<td align="char" char=".">90.4</td>
<td align="char" char=".">18.3</td>
<td align="char" char=".">22.8</td>
</tr>
<tr>
<td align="left">France</td>
<td align="center">5627</td>
<td align="center">50.4</td>
<td align="char" char=".">38.6</td>
<td align="char" char=".">30.9</td>
<td align="char" char=".">8.8</td>
<td align="char" char=".">27.5</td>
<td align="char" char=".">13.1</td>
<td align="char" char=".">6.7</td>
<td align="char" char=".">90.9</td>
<td align="char" char=".">13.0</td>
<td align="char" char=".">24.3</td>
</tr>
<tr>
<td align="left">Ireland</td>
<td align="center">4064</td>
<td align="center">38.9</td>
<td align="char" char=".">36.8</td>
<td align="char" char=".">37.3</td>
<td align="char" char=".">8.7</td>
<td align="char" char=".">21.1</td>
<td align="char" char=".">6.3</td>
<td align="char" char=".">6.9</td>
<td align="char" char=".">92.8</td>
<td align="char" char=".">23.8</td>
<td align="char" char=".">25.4</td>
</tr>
<tr>
<td align="left">Luxembourg</td>
<td align="center">3259</td>
<td align="center">47.4</td>
<td align="char" char=".">36.2</td>
<td align="char" char=".">34.6</td>
<td align="char" char=".">9.9</td>
<td align="char" char=".">25.8</td>
<td align="char" char=".">12.1</td>
<td align="char" char=".">6.8</td>
<td align="char" char=".">88.7</td>
<td align="char" char=".">22.7</td>
<td align="char" char=".">38.5</td>
</tr>
<tr>
<td align="left">Scotland</td>
<td align="center">5806</td>
<td align="center">50.3</td>
<td align="char" char=".">35.4</td>
<td align="char" char=".">32.4</td>
<td align="char" char=".">8.8</td>
<td align="char" char=".">31.4</td>
<td align="char" char=".">11.8</td>
<td align="char" char=".">4.9</td>
<td align="char" char=".">89.8</td>
<td align="char" char=".">17.6</td>
<td align="char" char=".">32.5</td>
</tr>
<tr>
<td align="left">Switzerland</td>
<td align="center">6592</td>
<td align="center">49.5</td>
<td align="char" char=".">36.0</td>
<td align="char" char=".">33.9</td>
<td align="char" char=".">9.6</td>
<td align="char" char=".">20.2</td>
<td align="char" char=".">8.1</td>
<td align="char" char=".">8.3</td>
<td align="char" char=".">90.8</td>
<td align="char" char=".">14.6</td>
<td align="char" char=".">38.6</td>
</tr>
<tr>
<td align="left">Wales</td>
<td align="center">5041</td>
<td align="center">51.0</td>
<td align="char" char=".">36.5</td>
<td align="char" char=".">27.7</td>
<td align="char" char=".">9.1</td>
<td align="char" char=".">35.5</td>
<td align="char" char=".">11.8</td>
<td align="char" char=".">4.2</td>
<td align="char" char=".">86.1</td>
<td align="char" char=".">16.4</td>
<td align="char" char=".">23.3</td>
</tr>
<tr>
<td align="left"><bold>Eastern Europe</bold></td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
</tr>
<tr>
<td align="left">Albania</td>
<td align="center">5011</td>
<td align="center">49.0</td>
<td align="char" char=".">33.1</td>
<td align="char" char=".">34.5</td>
<td align="char" char=".">4.9</td>
<td align="char" char=".">6.4</td>
<td align="char" char=".">0.8</td>
<td align="char" char=".">39.1</td>
<td align="char" char=".">95.6</td>
<td align="char" char=".">27.9</td>
<td align="char" char=".">10.2</td>
</tr>
<tr>
<td align="left">Armenia</td>
<td align="center">3640</td>
<td align="center">47.7</td>
<td align="char" char=".">31.7</td>
<td align="char" char=".">28.5</td>
<td align="char" char=".">5.3</td>
<td align="char" char=".">9.5</td>
<td align="char" char=".">0.1</td>
<td align="char" char=".">51.7</td>
<td align="char" char=".">97.6</td>
<td align="char" char=".">22.7</td>
<td align="char" char=".">9.4</td>
</tr>
<tr>
<td align="left">Bulgaria</td>
<td align="center">4586</td>
<td align="center">52.1</td>
<td align="char" char=".">32.3</td>
<td align="char" char=".">34.4</td>
<td align="char" char=".">6.8</td>
<td align="char" char=".">21.0</td>
<td align="char" char=".">5.1</td>
<td align="char" char=".">34.5</td>
<td align="char" char=".">57.8</td>
<td align="char" char=".">28.6</td>
<td align="char" char=".">16.0</td>
</tr>
<tr>
<td align="left">Croatia</td>
<td align="center">5696</td>
<td align="center">50.2</td>
<td align="char" char=".">34.9</td>
<td align="char" char=".">33.8</td>
<td align="char" char=".">7.2</td>
<td align="char" char=".">14.1</td>
<td align="char" char=".">4.2</td>
<td align="char" char=".">33.9</td>
<td align="char" char=".">88.4</td>
<td align="char" char=".">25.6</td>
<td align="char" char=".">17.6</td>
</tr>
<tr>
<td align="left">Czech Republic</td>
<td align="center">4999</td>
<td align="center">47.6</td>
<td align="char" char=".">34.0</td>
<td align="char" char=".">34.9</td>
<td align="char" char=".">8.0</td>
<td align="char" char=".">29.4</td>
<td align="char" char=".">12.0</td>
<td align="char" char=".">23.6</td>
<td align="char" char=".">86.8</td>
<td align="char" char=".">21.4</td>
<td align="char" char=".">21.9</td>
</tr>
<tr>
<td align="left">Hungary</td>
<td align="center">3845</td>
<td align="center">49.6</td>
<td align="char" char=".">34.8</td>
<td align="char" char=".">28.2</td>
<td align="char" char=".">6.4</td>
<td align="char" char=".">28.5</td>
<td align="char" char=".">10.2</td>
<td align="char" char=".">13.8</td>
<td align="char" char=".">85.2</td>
<td align="char" char=".">22.5</td>
<td align="char" char=".">21.2</td>
</tr>
<tr>
<td align="left">Republic of Moldova</td>
<td align="center">4472</td>
<td align="center">50.8</td>
<td align="char" char=".">33.3</td>
<td align="char" char=".">33.3</td>
<td align="char" char=".">5.3</td>
<td align="char" char=".">19.3</td>
<td align="char" char=".">4.7</td>
<td align="char" char=".">37.8</td>
<td align="char" char=".">84.4</td>
<td align="char" char=".">26.2</td>
<td align="char" char=".">12.1</td>
</tr>
<tr>
<td align="left">North Macedonia</td>
<td align="center">4137</td>
<td align="center">49.8</td>
<td align="char" char=".">31.5</td>
<td align="char" char=".">35.0</td>
<td align="char" char=".">6.9</td>
<td align="char" char=".">10.9</td>
<td align="char" char=".">0.6</td>
<td align="char" char=".">48.7</td>
<td align="char" char=".">100.0</td>
<td align="char" char=".">26.9</td>
<td align="char" char=".">14.4</td>
</tr>
<tr>
<td align="left">Poland</td>
<td align="center">4475</td>
<td align="center">49.7</td>
<td align="char" char=".">33.6</td>
<td align="char" char=".">32.8</td>
<td align="char" char=".">6.9</td>
<td align="char" char=".">20.6</td>
<td align="char" char=".">6.6</td>
<td align="char" char=".">23.5</td>
<td align="char" char=".">84.3</td>
<td align="char" char=".">24.2</td>
<td align="char" char=".">21.2</td>
</tr>
<tr>
<td align="left">Romania</td>
<td align="center">3824</td>
<td align="center">47.4</td>
<td align="char" char=".">31.4</td>
<td align="char" char=".">36.8</td>
<td align="char" char=".">5.6</td>
<td align="char" char=".">20.8</td>
<td align="char" char=".">3.9</td>
<td align="char" char=".">25.8</td>
<td align="char" char=".">76.6</td>
<td align="char" char=".">22.2</td>
<td align="char" char=".">16.1</td>
</tr>
<tr>
<td align="left">Russian Federation</td>
<td align="center">4616</td>
<td align="center">43.8</td>
<td align="char" char=".">38.2</td>
<td align="char" char=".">31.5</td>
<td align="char" char=".">6.2</td>
<td align="char" char=".">29.7</td>
<td align="char" char=".">10.6</td>
<td align="char" char=".">25.5</td>
<td align="char" char=".">85.2</td>
<td align="char" char=".">18.0</td>
<td align="char" char=".">16.7</td>
</tr>
<tr>
<td align="left">Slovakia</td>
<td align="center">6076</td>
<td align="center">50.3</td>
<td align="char" char=".">40.2</td>
<td align="char" char=".">30.6</td>
<td align="char" char=".">7.2</td>
<td align="char" char=".">22.4</td>
<td align="char" char=".">0.9</td>
<td align="char" char=".">0.8</td>
<td align="char" char=".">86.8</td>
<td align="char" char=".">25.1</td>
<td align="char" char=".">19.8</td>
</tr>
<tr>
<td align="left">Slovenia</td>
<td align="center">4950</td>
<td align="center">48.8</td>
<td align="char" char=".">34.8</td>
<td align="char" char=".">32.5</td>
<td align="char" char=".">9.0</td>
<td align="char" char=".">18.0</td>
<td align="char" char=".">6.1</td>
<td align="char" char=".">30.4</td>
<td align="char" char=".">87.6</td>
<td align="char" char=".">18.4</td>
<td align="char" char=".">20.9</td>
</tr>
<tr>
<td align="left">Ukraine</td>
<td align="center">4466</td>
<td align="center">47.4</td>
<td align="char" char=".">30.5</td>
<td align="char" char=".">36.9</td>
<td align="char" char=".">5.3</td>
<td align="char" char=".">25.6</td>
<td align="char" char=".">8.4</td>
<td align="char" char=".">34.4</td>
<td align="char" char=".">70.1</td>
<td align="char" char=".">26.2</td>
<td align="char" char=".">14.9</td>
</tr>
<tr>
<td align="left"><bold>Northern Europe</bold></td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
</tr>
<tr>
<td align="left">Denmark</td>
<td align="center">3867</td>
<td align="center">46.8</td>
<td align="char" char=".">35.3</td>
<td align="char" char=".">32.9</td>
<td align="char" char=".">9.2</td>
<td align="char" char=".">24.2</td>
<td align="char" char=".">10.1</td>
<td align="char" char=".">1.2</td>
<td align="char" char=".">93.6</td>
<td align="char" char=".">13.2</td>
<td align="char" char=".">41.6</td>
</tr>
<tr>
<td align="left">Estonia</td>
<td align="center">3980</td>
<td align="center">50.3</td>
<td align="char" char=".">35.3</td>
<td align="char" char=".">31.1</td>
<td align="char" char=".">7.5</td>
<td align="char" char=".">32.1</td>
<td align="char" char=".">14.0</td>
<td align="char" char=".">16.5</td>
<td align="char" char=".">84.7</td>
<td align="char" char=".">16.6</td>
<td align="char" char=".">23.2</td>
</tr>
<tr>
<td align="left">Finland</td>
<td align="center">5878</td>
<td align="center">49.2</td>
<td align="char" char=".">32.4</td>
<td align="char" char=".">33.7</td>
<td align="char" char=".">8.4</td>
<td align="char" char=".">24.4</td>
<td align="char" char=".">14.5</td>
<td align="char" char=".">4.5</td>
<td align="char" char=".">94.2</td>
<td align="char" char=".">27.9</td>
<td align="char" char=".">39.6</td>
</tr>
<tr>
<td align="left">Greenland</td>
<td align="center">927</td>
<td align="center">47.6</td>
<td align="char" char=".">36.8</td>
<td align="char" char=".">30.7</td>
<td align="char" char=".">5.8</td>
<td align="char" char=".">38.3</td>
<td align="char" char=".">15.2</td>
<td align="char" char=".">8.9</td>
<td align="char" char=".">90.8</td>
<td align="char" char=".">17.3</td>
<td align="char" char=".">17.2</td>
</tr>
<tr>
<td align="left">Iceland</td>
<td align="center">10490</td>
<td align="center">50.0</td>
<td align="char" char=".">35.3</td>
<td align="char" char=".">31.7</td>
<td align="char" char=".">8.5</td>
<td align="char" char=".">27.7</td>
<td align="char" char=".">13.5</td>
<td align="char" char=".">2.7</td>
<td align="char" char=".">91.1</td>
<td align="char" char=".">22.5</td>
<td align="char" char=".">24.9</td>
</tr>
<tr>
<td align="left">Lithuania</td>
<td align="center">5578</td>
<td align="center">50.8</td>
<td align="char" char=".">35.3</td>
<td align="char" char=".">29.4</td>
<td align="char" char=".">8.1</td>
<td align="char" char=".">27.0</td>
<td align="char" char=".">8.9</td>
<td align="char" char=".">24.4</td>
<td align="char" char=".">86.4</td>
<td align="char" char=".">20.8</td>
<td align="char" char=".">28.8</td>
</tr>
<tr>
<td align="left">Latvia</td>
<td align="center">5375</td>
<td align="center">47.8</td>
<td align="char" char=".">35.2</td>
<td align="char" char=".">31.0</td>
<td align="char" char=".">6.5</td>
<td align="char" char=".">32.6</td>
<td align="char" char=".">11.5</td>
<td align="char" char=".">22.2</td>
<td align="char" char=".">78.7</td>
<td align="char" char=".">18.7</td>
<td align="char" char=".">19.8</td>
</tr>
<tr>
<td align="left">Norway</td>
<td align="center">3380</td>
<td align="center">48.7</td>
<td align="char" char=".">30.8</td>
<td align="char" char=".">28.8</td>
<td align="char" char=".">9.8</td>
<td align="char" char=".">19.9</td>
<td align="char" char=".">9.8</td>
<td align="char" char=".">4.6</td>
<td align="char" char=".">93.1</td>
<td align="char" char=".">18.9</td>
<td align="char" char=".">46.4</td>
</tr>
<tr>
<td align="left">Sweden</td>
<td align="center">7515</td>
<td align="center">49.6</td>
<td align="char" char=".">29.6</td>
<td align="char" char=".">36.3</td>
<td align="char" char=".">9.2</td>
<td align="char" char=".">28.2</td>
<td align="char" char=".">10.7</td>
<td align="char" char=".">2.1</td>
<td align="char" char=".">93.2</td>
<td align="char" char=".">14.2</td>
<td align="char" char=".">36.0</td>
</tr>
<tr>
<td align="left"><bold>Southern Europe</bold></td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
<td align="left"/>
</tr>
<tr>
<td align="left">Greece</td>
<td align="center">4098</td>
<td align="center">49.7</td>
<td align="char" char=".">35.0</td>
<td align="char" char=".">32.0</td>
<td align="char" char=".">6.6</td>
<td align="char" char=".">14.0</td>
<td align="char" char=".">3.5</td>
<td align="char" char=".">17.5</td>
<td align="char" char=".">86.3</td>
<td align="char" char=".">13.5</td>
<td align="char" char=".">24.9</td>
</tr>
<tr>
<td align="left">Israel</td>
<td align="center">6148</td>
<td align="center">48.6</td>
<td align="char" char=".">30.1</td>
<td align="char" char=".">30.1</td>
<td align="char" char=".">7.7</td>
<td align="char" char=".">13.3</td>
<td align="char" char=".">3.6</td>
<td align="char" char=".">6.0</td>
<td align="char" char=".">100.0</td>
<td align="char" char=".">12.4</td>
<td align="char" char=".">23.3</td>
</tr>
<tr>
<td align="left">Italy</td>
<td align="center">4024</td>
<td align="center">50.3</td>
<td align="char" char=".">35.1</td>
<td align="char" char=".">31.6</td>
<td align="char" char=".">7.5</td>
<td align="char" char=".">15.7</td>
<td align="char" char=".">3.3</td>
<td align="char" char=".">16.9</td>
<td align="char" char=".">86.3</td>
<td align="char" char=".">10.3</td>
<td align="char" char=".">22.8</td>
</tr>
<tr>
<td align="left">Malta</td>
<td align="center">2214</td>
<td align="center">51.4</td>
<td align="char" char=".">35.8</td>
<td align="char" char=".">28.2</td>
<td align="char" char=".">9.2</td>
<td align="char" char=".">11.8</td>
<td align="char" char=".">1.4</td>
<td align="char" char=".">2.7</td>
<td align="char" char=".">78.4</td>
<td align="char" char=".">18.0</td>
<td align="char" char=".">17.7</td>
</tr>
<tr>
<td align="left">Portugal</td>
<td align="center">4910</td>
<td align="center">47.4</td>
<td align="char" char=".">39.8</td>
<td align="char" char=".">27.1</td>
<td align="char" char=".">8.5</td>
<td align="char" char=".">24.0</td>
<td align="char" char=".">8.8</td>
<td align="char" char=".">14.6</td>
<td align="char" char=".">77.3</td>
<td align="char" char=".">15.6</td>
<td align="char" char=".">15.7</td>
</tr>
<tr>
<td align="left">Spain</td>
<td align="center">10956</td>
<td align="center">49.2</td>
<td align="char" char=".">38.8</td>
<td align="char" char=".">33.9</td>
<td align="char" char=".">8.2</td>
<td align="char" char=".">18.5</td>
<td align="char" char=".">5.6</td>
<td align="char" char=".">10.8</td>
<td align="center">- <xref ref-type="table-fn" rid="t001fn002"><sup>a</sup></xref></td>
<td align="char" char=".">26.1</td>
<td align="char" char=".">23.5</td>
</tr>
<tr>
<td align="left">Total</td>
<td align="center">211798</td>
<td align="center">49.2</td>
<td align="char" char=".">34.6</td>
<td align="char" char=".">33.1</td>
<td align="char" char=".">7.9</td>
<td align="char" char=".">23.2</td>
<td align="char" char=".">8.7</td>
<td align="char" char=".">15.6</td>
<td align="char" char=".">83.2</td>
<td align="char" char=".">20.4</td>
<td align="char" char=".">25.4</td>
</tr>
<tr>
<td align="left">%missing</td>
<td align="center">-</td>
<td align="center">0</td>
<td align="char" char=".">0.8</td>
<td align="left"/>
<td align="char" char=".">8.3</td>
<td align="char" char=".">4.6</td>
<td align="char" char=".">4.6</td>
<td align="char" char=".">4.6</td>
<td align="char" char=".">5.7</td>
<td align="char" char=".">2.8</td>
<td align="char" char=".">5.3</td>
</tr>
</tbody>
</table>
</alternatives>
<table-wrap-foot>
<fn id="t001fn001"><p>* The reference groups (girls, 11-year-olds, living with both parents) are not presented.</p></fn>
<fn id="t001fn002"><p><sup>a</sup> Incomplete data on siblings.</p></fn>
</table-wrap-foot>
</table-wrap>
<sec id="sec017">
<title>Family structure differences in MVPA</title>
<p>As shown in <xref ref-type="table" rid="pone.0300188.t002">Table 2</xref> (model 1), the unadjusted analysis indicated that adolescents living with one versus two parents had a lower likelihood of daily 60 min MVPA. However, after accounting for covariates, the association was no longer statistically significant (model 2). The results of model 2 indicated that having sibling(s) in the main home (IRR = 1.11, 95% CI: 1.07, 1.14), higher individual-level SES (IRR = 1.05, 95% CI: 1.04, 1.05), and being a boy (IRR = 1.60, 95% CI: 1.57, 1.64) were associated with a greater likelihood of daily 60 min MVPA, while 13-year-olds (IRR = 0.77, 95% CI: 0.75, 0.79) and 15-year-olds (IRR = 0.61, 95% CI: 0.59, 0.63) were associated with a lower likelihood of daily MVPA than 11-year-olds.</p>
<table-wrap id="pone.0300188.t002" position="float">
<object-id pub-id-type="doi">10.1371/journal.pone.0300188.t002</object-id>
<label>Table 2</label> <caption><title>Crude and adjusted model for associations between family structure and daily 60 min MVPA, all countries.</title></caption>
<alternatives>
<graphic id="pone.0300188.t002g" mimetype="image" position="float" xlink:href="info:doi/10.1371/journal.pone.0300188.t002" xlink:type="simple"/>
<table>
<colgroup>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
</colgroup>
<thead>
<tr>
<th align="left" rowspan="2"/>
<th align="center" colspan="2">Model 1</th>
<th align="center" colspan="2">Model 2</th>
<th align="center" colspan="2">Model 3</th>
<th align="center" colspan="2">Model 4b</th>
</tr>
<tr>
<th align="center">IRR</th>
<th align="center">95% CI</th>
<th align="center">IRR</th>
<th align="center">95% CI</th>
<th align="center">IRR</th>
<th align="center">95% CI</th>
<th align="center">IRR</th>
<th align="center">95% CI</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left">One parent in the main home</td>
<td align="char" char=".">0.91<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.89,0.93]</td>
<td align="char" char=".">0.98</td>
<td align="center">[0.96,1.01]</td>
<td align="char" char=".">0.84</td>
<td align="center">[0.67,1.05]</td>
<td align="char" char=".">1.05</td>
<td align="center">[0.99,1.11]</td>
</tr>
<tr>
<td align="left">Boys</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">1.60<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[1.57,1.64]</td>
<td align="char" char=".">1.62<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[1.58,1.66]</td>
<td align="char" char=".">1.62<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[1.58,1.66]</td>
</tr>
<tr>
<td align="left">13 yr olds</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.77<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.75,0.79]</td>
<td align="char" char=".">0.77<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.75,0.79]</td>
<td align="char" char=".">0.77<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.75,0.79]</td>
</tr>
<tr>
<td align="left">15 yr olds</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.61<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.59,0.63]</td>
<td align="char" char=".">0.61<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.59,0.62]</td>
<td align="char" char=".">0.61<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.59,0.63]</td>
</tr>
<tr>
<td align="left">Individual-level SES</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">1.05<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[1.04,1.05]</td>
<td align="char" char=".">1.05<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[1.05,1.06]</td>
<td align="char" char=".">1.05<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[1.05,1.06]</td>
</tr>
<tr>
<td align="left">Stepparent in the main home</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.99</td>
<td align="center">[0.95,1.03]</td>
<td align="char" char=".">0.99</td>
<td align="center">[0.95,1.03]</td>
<td align="char" char=".">0.99</td>
<td align="center">[0.96,1.03]</td>
</tr>
<tr>
<td align="left">Grandparent (s) in the main home</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">1.02</td>
<td align="center">[0.99,1.04]</td>
<td align="char" char=".">1.02</td>
<td align="center">[0.99,1.04]</td>
<td align="char" char=".">1.02</td>
<td align="center">[0.99,1.04]</td>
</tr>
<tr>
<td align="left">Siblings(s) in the main home</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">1.11<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[1.07,1.14]</td>
<td align="char" char=".">1.11<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[1.07,1.14]</td>
<td align="char" char=".">1.11<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[1.07,1.14]</td>
</tr>
<tr>
<td align="left">One parent x boys</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.95<xref ref-type="table-fn" rid="t002fn004">*</xref></td>
<td align="center">[0.91,1.00]</td>
<td align="char" char=".">0.95<xref ref-type="table-fn" rid="t002fn004">*</xref></td>
<td align="center">[0.91,1.00]</td>
</tr>
<tr>
<td align="left">One parent x Individual-level SES</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.99<xref ref-type="table-fn" rid="t002fn004">*</xref></td>
<td align="center">[0.98,1.00]</td>
<td align="char" char=".">0.99<xref ref-type="table-fn" rid="t002fn004">*</xref></td>
<td align="center">[0.98,1.00]</td>
</tr>
<tr>
<td align="left">One parent x Country-level SES</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.99</td>
<td align="center">[0.96,1.02]</td>
</tr>
<tr>
<td align="left">One parent x Eastern Europe</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.95</td>
<td align="center">[0.87,1.04]</td>
</tr>
<tr>
<td align="left">One parent x Northern Europe</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.93<xref ref-type="table-fn" rid="t002fn004">*</xref></td>
<td align="center">[0.87,0.99]</td>
</tr>
<tr>
<td align="left">One parent x Southern Europe</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.96</td>
<td align="center">[0.88,1.06]</td>
</tr>
<tr>
<td align="left">Constant</td>
<td align="char" char=".">0.27<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.25,0.29]</td>
<td align="char" char=".">0.24<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.22,0.26]</td>
<td align="char" char=".">0.24<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.22,0.26]</td>
<td align="char" char=".">0.24<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.22,0.25]</td>
</tr>
<tr>
<td align="left">Variance estimates</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
</tr>
<tr>
<td align="left">Random intercept</td>
<td align="char" char=".">0.08<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.07,0.09]</td>
<td align="char" char=".">0.03<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.02,0.04]</td>
<td align="char" char=".">0.03<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.02,0.04]</td>
<td align="char" char=".">0.03<xref ref-type="table-fn" rid="t002fn002">***</xref></td>
<td align="center">[0.02,0.04]</td>
</tr>
</tbody>
</table>
</alternatives>
<table-wrap-foot>
<fn id="t002fn001"><p>Note: Reference categories: gender; girls, age; 11-year-olds, family structure; both parents in the main home. Country fixed effects are not shown for models 1–4. Model 4a not presented. Country x family structure (one parent) interaction is not shown for model 3.</p></fn>
<fn id="t002fn002"><p>*** p&lt;0.001,</p></fn>
<fn id="t002fn003"><p>**p&lt;0.01,</p></fn>
<fn id="t002fn004"><p>*p&lt;0.05</p></fn>
</table-wrap-foot>
</table-wrap>
<p>The interaction analysis showed that the strength of the association between living with one versus two parents and MVPA was more pronounced in boys than girls (Wald test for gender interaction: (χ<sup>2</sup>(1) = 4.19, <italic>p</italic> = 0.04)). The model-derived conditional IRR for boys was statistically significant (IRR = 0.96, 95% CI: 0.92, 0.99), whereas the conditional IRR for girls was not (IRR = 1.00, 95% CI: 0.96, 1.04). The association between living with one versus two parents and MVPA also differed across individual-level SES (Wald test for SES interaction: (χ<sup>2</sup>(1) = 5.85 <italic>p</italic> = .02)). As shown in <xref ref-type="fig" rid="pone.0300188.g001">Fig 1</xref>, the conditional effect was most pronounced for adolescents with higher SES scores. For adolescents with a group-mean centred SES score of +5, the conditional IRR was 0.92 (<italic>p</italic> &lt; .05). In contrast, the IRR for adolescents with group-mean centred SES score of -5 (low) was 1.04 (ns). The 2-way interactions between family structure (one parent) and age (χ<sup>2</sup>(2) = 0.31, <italic>p</italic> = 0.86), having a stepparent in the main home (χ<sup>2</sup>(1) = 0.53, <italic>p</italic> = 0.47), having grandparent(s) in the main home (χ<sup>2</sup>(1) = 0.00, <italic>p</italic> = 0.98), and having a sibling(s) in the main home (χ<sup>2</sup>(1) = 0.63, <italic>p</italic> = 0.43) were all not statistically significant and were therefore not included in models 3 and 4.</p>
<fig id="pone.0300188.g001" position="float">
<object-id pub-id-type="doi">10.1371/journal.pone.0300188.g001</object-id>
<label>Fig 1</label>
<caption>
<title>Conditional marginal effects of living in one versus two parents on daily 60 min MVPA by individual-level SES (FAS) (estimates derived from model 3).</title>
</caption>
<graphic mimetype="image" position="float" xlink:href="info:doi/10.1371/journal.pone.0300188.g001" xlink:type="simple"/>
</fig>
</sec>
<sec id="sec018">
<title>Cross-national differences in MVPA</title>
<p>The interaction between family structure and country was also statistically significant χ<sup>2</sup>(40) = 58.01, p = 0.03) and included in model 3 (not shown in <xref ref-type="table" rid="pone.0300188.t002">Table 2</xref>). However, when analysing country by country, the association was no longer statistically significant in the majority of countries (<xref ref-type="fig" rid="pone.0300188.g002">Fig 2</xref>). Living with one parent was only associated with a lower likelihood of MVPA in Norway, Bulgaria and Iceland (estimate points to the left of the red line), whereas living with one parent was associated with a higher likelihood of MVPA in French Belgium. The cross-national variation in the relationship between one-parent families and MVPA could not be explained by region (Wald-test: χ<sup>2</sup>(3) = 4.97, p = 0.17) (model 4a, not shown in <xref ref-type="table" rid="pone.0300188.t002">Table 2</xref>) or country-level SES (<xref ref-type="table" rid="pone.0300188.t002">Table 2</xref>).</p>
<fig id="pone.0300188.g002" position="float">
<object-id pub-id-type="doi">10.1371/journal.pone.0300188.g002</object-id>
<label>Fig 2</label>
<caption>
<title>Associations between living with one versus two parents and 60 min MVPA across countries, adjusted for co-variates (estimates were derived from model 3).</title>
</caption>
<graphic mimetype="image" position="float" xlink:href="info:doi/10.1371/journal.pone.0300188.g002" xlink:type="simple"/>
</fig>
</sec>
<sec id="sec019">
<title>Family structure differences in VPA</title>
<p>As shown in <xref ref-type="table" rid="pone.0300188.t003">Table 3</xref>, the adjusted analysis (model 2) indicated that living with one parent in the main home (IRR = 0.93, 95% CI: 0.91,0.95) and grandparents in the main home (IRR = 0.91, 95% CI: 0.89,0.94) were both associated with a lower likelihood of &gt; 4 times/week VPA, while higher individual-level SES (IRR = 1.10, 95% CI: 1.09, 1.10), being a boy (IRR = 1.49, 95% CI: 1.46,1.51), age 13 (IRR = 1.13, 95% CI: 1.11, 1.16) and age 15 (IRR = 1.10, 95% CI: 1.07, 1.12) were associated with a higher IRR for VPA.</p>
<table-wrap id="pone.0300188.t003" position="float">
<object-id pub-id-type="doi">10.1371/journal.pone.0300188.t003</object-id>
<label>Table 3</label> <caption><title>Crude and adjusted model for associations between family structure and VPA ≥ 4 times/week, all countries.</title></caption>
<alternatives>
<graphic id="pone.0300188.t003g" mimetype="image" position="float" xlink:href="info:doi/10.1371/journal.pone.0300188.t003" xlink:type="simple"/>
<table>
<colgroup>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
<col align="left" valign="middle"/>
</colgroup>
<thead>
<tr>
<th align="left"/>
<th align="center" colspan="2">Model 1</th>
<th align="center" colspan="2">Model 2</th>
<th align="center" colspan="2">Model 3</th>
<th align="center" colspan="2">Model 4b</th>
</tr>
<tr>
<th align="left"/>
<th align="center">IRR</th>
<th align="center">95% CI</th>
<th align="center">IRR</th>
<th align="center">95% CI</th>
<th align="center">IRR</th>
<th align="center">95% CI</th>
<th align="center">IRR</th>
<th align="center">95% CI</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left">One parent in the main home</td>
<td align="char" char=".">0.85<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.84,0.87]</td>
<td align="char" char=".">0.93<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.91,0.95]</td>
<td align="char" char=".">1.04</td>
<td align="center">[0.71,1.51]</td>
<td align="char" char=".">0.99</td>
<td align="center">[0.93,1.05]</td>
</tr>
<tr>
<td align="left">Boys</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">1.49<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.46,1.51]</td>
<td align="char" char=".">1.49<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.46,1.51]</td>
<td align="char" char=".">1.49<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.46,1.51]</td>
</tr>
<tr>
<td align="left">13 yr olds</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">1.13<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.11,1.16]</td>
<td align="char" char=".">1.13<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.11,1.16]</td>
<td align="char" char=".">1.13<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.11,1.16]</td>
</tr>
<tr>
<td align="left">15 yr olds</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">1.10<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.07,1.12]</td>
<td align="char" char=".">1.10<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.07,1.12]</td>
<td align="char" char=".">1.10<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.07,1.12]</td>
</tr>
<tr>
<td align="left">Individual-level SES</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">1.10<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.09,1.10]</td>
<td align="char" char=".">1.10<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.09,1.10]</td>
<td align="char" char=".">1.10<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[1.09,1.10]</td>
</tr>
<tr>
<td align="left">Stepparent in the main home</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.97</td>
<td align="center">[0.94,1.00]</td>
<td align="char" char=".">0.97</td>
<td align="center">[0.94,1.00]</td>
<td align="char" char=".">0.97</td>
<td align="center">[0.94,1.00]</td>
</tr>
<tr>
<td align="left">Grandparent(s) in the main home</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.91<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.89,0.94]</td>
<td align="char" char=".">0.91<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.89,0.94]</td>
<td align="char" char=".">0.91<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.89,0.94]</td>
</tr>
<tr>
<td align="left">Sibling(s) in the main home</td>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">1.01</td>
<td align="center">[0.98,1.03]</td>
<td align="char" char=".">1.03</td>
<td align="center">[1.00,1.06]</td>
<td align="char" char=".">1.02</td>
<td align="center">[0.99,1.05]</td>
</tr>
<tr>
<td align="left">One parent x sibling(s) in the main home</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.94<xref ref-type="table-fn" rid="t003fn004">*</xref></td>
<td align="center">[0.89,0.99]</td>
<td align="char" char=".">0.95</td>
<td align="center">[0.90,1.01]</td>
</tr>
<tr>
<td align="left">One parent x Country-level SES</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.96<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.93,0.98]</td>
</tr>
<tr>
<td align="left">One parent x Eastern Europe</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.99</td>
<td align="center">[0.92,1.07]</td>
</tr>
<tr>
<td align="left">One parent x Northern Europe</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.99</td>
<td align="center">[0.94,1.04]</td>
</tr>
<tr>
<td align="left">One parent x Southern Europe</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="char" char=".">0.97</td>
<td align="center">[0.89,1.05]</td>
</tr>
<tr>
<td align="left">Constant</td>
<td align="char" char=".">0.10<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.09,0.11]</td>
<td align="char" char=".">0.08<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.07,0.09]</td>
<td align="char" char=".">0.08<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.07,0.09]</td>
<td align="char" char=".">0.08<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.07,0.09]</td>
</tr>
<tr>
<td align="left">Variance estimates</td>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
<td align="center"/>
</tr>
<tr>
<td align="left">Random intercept</td>
<td align="char" char=".">0.03<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.02,0.04]</td>
<td align="char" char=".">0.00</td>
<td align="left">[-0.01,0.01]</td>
<td align="char" char=".">0.00<xref ref-type="table-fn" rid="t003fn002">***</xref></td>
<td align="center">[0.00,0.00]</td>
<td align="char" char=".">0.00</td>
<td align="center">[-0.01,0.01]</td>
</tr>
</tbody>
</table>
</alternatives>
<table-wrap-foot>
<fn id="t003fn001"><p>Note: Reference categories: gender; girls, age; 11-year-olds, family structure; both parents in the main home. Country fixed effects are not shown for models 1–4. Country x One parent interaction is not shown for model 3.</p></fn>
<fn id="t003fn002"><p>*** p&lt;0.001,</p></fn>
<fn id="t003fn003"><p>**p&lt;0.01,</p></fn>
<fn id="t003fn004"><p>*p&lt;0.05</p></fn>
</table-wrap-foot>
</table-wrap>
<p>The interaction analysis showed that the strength of the association between living with one versus two parents and VPA was more pronounced for adolescents with sibling(s) than those without sibling(s) (Wald test for siblings interaction: (χ<sup>2</sup>(1) = 4.19, <italic>p</italic> = 0.04)). The model-derived conditional IRR for those with sibling(s) was statistically significant (IRR = 0.93, 95% CI: 0.91, 0.96), whereas the conditional IRR for those without sibling(s) was not (IRR = 1.00, 95% CI: 0.94, 1.05). There were no significant interactions between living with one parent in the main home and gender (χ2(1) = 0.34, p = 0.56), individual-level SES (χ2(1) = 0.21, p = 0.65), age (χ2(2) = 4.03, p = 0.13), living with a stepparent in the main home (χ2(1) = 3.18, p = .07), and living with grandparent(s) in the main home (χ2(1) = .2.28, p = .13). These interaction terms were therefore not included in subsequent models.</p>
</sec>
<sec id="sec020">
<title>Cross-national differences in VPA</title>
<p>The interaction between living with one parent in the main home and country was statistically significant (Model 3, not shown in <xref ref-type="table" rid="pone.0300188.t003">Table 3</xref>, Wald test: χ<sup>2</sup>(40) = 84.238, <italic>p</italic>&lt;0.001)). As shown in <xref ref-type="fig" rid="pone.0300188.g003">Fig 3</xref>, living with one versus two parents was associated with a lower IRR for &gt; 4 times/week VPA in fourteen countries, including all countries in the Northern European region, except Denmark, whereas living with one parent was associated with a higher IRR for &gt; 4 times/week VPA in the Russian Federation only. The association between living in a one versus a two-parent family and VPA was not statistically significant for the remaining countries.</p>
<fig id="pone.0300188.g003" position="float">
<object-id pub-id-type="doi">10.1371/journal.pone.0300188.g003</object-id>
<label>Fig 3</label>
<caption>
<title>Associations between living with one parent versus two parents and ≥ 4 times/week VPA across countries, adjusted for covariates.</title>
</caption>
<graphic mimetype="image" position="float" xlink:href="info:doi/10.1371/journal.pone.0300188.g003" xlink:type="simple"/>
</fig>
<p>The cross-national variation in the relationship between VPA and one- versus two-parent families could partly be explained by geographical region (Wald-test: χ<sup>2</sup>(3) = 9.16.55, <italic>p</italic> = 0.03), with a significantly different relationship between one versus two parents and VPA observed in Eastern Europe as compared to Western Europe (reference category, model 4a, not shown in <xref ref-type="table" rid="pone.0300188.t003">Table 3</xref>). The model-derived conditional IRR of one parent was statistically significant for Western Europe (IRR = 0.93, 95% CI: 0.89,0.96) and Northern Europe (IRR = 0.94, 95% CI: 0.90,0.98) but not for Eastern Europe (IRR = 1.01, 95% CI: 0.96,1.06) and Southern Europe (IRR = 0.94, 95% CI: 0.88,1.01). After adding country-level SES to the model, the interaction between family structure (one versus two parents) and the geographical region became non-significant, suggesting that this association could largely be explained by differences in country-level SES between regions (IRR = 0.96, 95% CI: 0.93, 0.98), model 4b, see <xref ref-type="table" rid="pone.0300188.t003">Table 3</xref>). As shown in <xref ref-type="fig" rid="pone.0300188.g004">Fig 4</xref>, the association between living with one parent and VPA was most pronounced in countries with higher mean SES scores. For example, the conditional IRR in countries with lower country-level SES (-2) was 1.04 (ns), whereas the conditional IRR was 0.86 (<italic>p</italic>&lt;0.05) in countries with high country-level SES (+2).</p>
<fig id="pone.0300188.g004" position="float">
<object-id pub-id-type="doi">10.1371/journal.pone.0300188.g004</object-id>
<label>Fig 4</label>
<caption>
<title>Conditional marginal effects of living with one versus two parents on ≥ 4 times/week VPA by country-level SES (FAS) (estimates derived from model 4b).</title>
</caption>
<graphic mimetype="image" position="float" xlink:href="info:doi/10.1371/journal.pone.0300188.g004" xlink:type="simple"/>
</fig>
</sec>
</sec>
<sec id="sec021" sec-type="conclusions">
<title>Discussion</title>
<p>This is the first large-scale cross-country study examining the associations between family structure and adolescent PA. Through pooling data from 40 European countries and Canada, significant associations were observed for some family structures and daily 60 min MVPA as well as ≥ 4 times/week VPA. Cross-country variations in the relationship between living with one versus two parents and PA were notable, most pronounced for VPA. These findings were related to geographical regions and largely explained by country-level SES.</p>
<sec id="sec022">
<title>Associations between family structure and PA</title>
<p>In the pooled analyses, a differential gender effect was observed, with a lower likelihood for daily 60 min MVPA only for boys living with one parent compared to two parents in the main home. Previous studies have, to a limited extent, examined gender differences in the relationship between family structure and indicators of PA. In an English study, boys, but not girls living with a single parent compared to two parents, spent more time on sedentary behaviours in general and on screen time on weekdays and weekends [<xref ref-type="bibr" rid="pone.0300188.ref030">30</xref>]. In accordance with the displacement hypothesis, sedentary activities may replace time spent on PA [<xref ref-type="bibr" rid="pone.0300188.ref059">59</xref>]. Thus, increased screen use among boys living with one parent could be one possible explanation for the current study findings that should be further examined.</p>
<p>Another reason for a lower likelihood of daily 60 min MVPA for boys living with one compared to two parents may relate to more boys than girls participating in sport [<xref ref-type="bibr" rid="pone.0300188.ref037">37</xref>, <xref ref-type="bibr" rid="pone.0300188.ref060">60</xref>, <xref ref-type="bibr" rid="pone.0300188.ref061">61</xref>]. Also, studies suggest that boys accrue more MVPA minutes during training than girls [<xref ref-type="bibr" rid="pone.0300188.ref062">62</xref>]. If sport participation constitutes a larger part of boys’ overall MVPA, a reduced capacity to follow up and support sport involvement in one-parent compared to two-parent families could impact their MVPA. The finding of a lower likelihood of ≥ 4 times/week VPA for adolescents living with one versus two parents in the current study may suggest so. Engaging more often in leisure time VPA reflects frequent and regular involvement in PA, typically for organised sport activities that demand greater parental support. Children in one-parent families have reported experiencing more barriers to engaging in physical activities due to less parental support caused by a lack of free time, workload, and household responsibilities [<xref ref-type="bibr" rid="pone.0300188.ref063">63</xref>]. This can lead to fewer opportunities to support the children in sport, such as transporting them to and from leisure time activities, cheering during competitions, and doing PA with them [<xref ref-type="bibr" rid="pone.0300188.ref064">64</xref>]. Lower levels of sport involvement in one-parent compared to two-parent households align with studies from countries with various social and socioeconomic contexts [<xref ref-type="bibr" rid="pone.0300188.ref032">32</xref>–<xref ref-type="bibr" rid="pone.0300188.ref038">38</xref>]. Another possibility could be centred on children with two parents who live with only one or mainly one, as extra effort is needed to maintain participation in organised sport [<xref ref-type="bibr" rid="pone.0300188.ref032">32</xref>]. Time to travel to visit biological parents has been reported as a factor restricting engagement in PA among children in non-traditional families [<xref ref-type="bibr" rid="pone.0300188.ref063">63</xref>].</p>
<p>Additionally, a factor that has been hypothesised to impact children’s PA engagement is the family sport culture, described as the family’s fundamental role in establishing deeply embodied motivations, habits, and lifestyles [<xref ref-type="bibr" rid="pone.0300188.ref065">65</xref>]. Strandbu and colleagues (2020] demonstrate the sustained importance of family sport culture for adolescents’ involvement in sport over time [<xref ref-type="bibr" rid="pone.0300188.ref065">65</xref>]. One could assume that those living with one parent would have reduced chances of experiencing a sporting culture at home compared to those living with two parents. Single parents may also have less time to be physically active role models.</p>
<p>In the current study, the association between family structure and MVPA differed across individual-level SES, with the conditional effect of family structure (living with one versus two parents) most pronounced for those with higher SES scores. Being affluent typically strengthens the ability to cover financial outlay (e.g. sport equipment, membership, fees), and indeed, high individual-level SES was a predictor for MVPA and VPA in the current study. Nevertheless, not having the benefit of a two-parent family structure to contribute to additional support for an active lifestyle may increase the differences and explain the more substantial effect of living with two compared to one parent on MVPA, especially within the high SES group. An interaction effect of individual-level SES on VPA was, however, not observed.</p>
<p>Interestingly, there were no beneficial effects on MVPA and VPA of having a stepparent in the main home. This may seem surprising as stepparents could contribute with time, economic resources, and sport culture by role-modelling PA habits. Similar findings were reported for organised sport involvement among Canadian [<xref ref-type="bibr" rid="pone.0300188.ref032">32</xref>] and Norwegian [<xref ref-type="bibr" rid="pone.0300188.ref038">38</xref>] adolescents. The reasons are likely to be complex. It may be explained by underlying processes in reconstructed families and the role the family climate may play [<xref ref-type="bibr" rid="pone.0300188.ref066">66</xref>]. For example, studies have indicated that stepparents are, in general, less committed to their non-biological children [<xref ref-type="bibr" rid="pone.0300188.ref041">41</xref>, <xref ref-type="bibr" rid="pone.0300188.ref067">67</xref>], reducing the potential parent-child dyad strength in support for PA of the adolescent [<xref ref-type="bibr" rid="pone.0300188.ref068">68</xref>]. Programmes that target improving relations between stepparents and their non-biological children may reverse this trend. Another aspect is that a reconstructed family may have difficulties and need time to form relationships between the stepparent and stepchild that facilitate PA [<xref ref-type="bibr" rid="pone.0300188.ref069">69</xref>].</p>
<p>Although the entire family unit is regarded as especially important in endorsing PA behaviours [<xref ref-type="bibr" rid="pone.0300188.ref013">13</xref>], research has primarily addressed the role of the parents only. However, sibling relations are reciprocal and dynamic and can contribute to PA through peer modelling, encouraging active transport, the opportunity for playmates and serving as additional caregivers [<xref ref-type="bibr" rid="pone.0300188.ref012">12</xref>, <xref ref-type="bibr" rid="pone.0300188.ref070">70</xref>]. In our pooled analysis, having siblings in the main home increased the likelihood of MVPA compared to not having a sibling(s). This aligns with a recent meta-analysis that found children with siblings having higher PA levels, as measured by accelerometer or pedometer [<xref ref-type="bibr" rid="pone.0300188.ref070">70</xref>]. A direct effect of having sibling(s) in the main house was not observed for leisure time VPA for at least 4 timers/week. However, the strength of the association between living with one versus two parents and VPA was more pronounced for adolescents with siblings than those without siblings, with a significant negative impact on VPA of having siblings in the main home observed. This finding somewhat nuances the existing literature where a positive relationship has been found between having a sibling and children’s participation in sport [<xref ref-type="bibr" rid="pone.0300188.ref012">12</xref>]. It should be mentioned that our outcome measure, ≥ 4 times/week VPA, reflects a relatively high level of PA engagement that may be less feasible for adolescents in one-parent families with siblings, particularly if it demands substantial parental support regarding time and logistics.</p>
<p>The focus on grandparents’ influence on obesity-related health behaviours has been mainly on children’s diet behaviour and weight, with varying results across ethnicities and countries [<xref ref-type="bibr" rid="pone.0300188.ref071">71</xref>]. In the current study, living with grandparent(s) in the main house was unrelated to MVPA, and negatively associated with VPA. These findings partly contrast the results from a former HBSC survey of a US sample of Latino school-children that found a higher OR of daily 60 min MVPA but no association with VPA among those living with grandparents in the house [<xref ref-type="bibr" rid="pone.0300188.ref072">72</xref>].</p>
</sec>
<sec id="sec023">
<title>Cross-country variations</title>
<p>The association between living with one versus two parents and PA varied across countries. Still, it was not statistically significant in most countries. The likelihood of daily 60 min MVPA among adolescents living with one parent was only significantly lower in three countries, whereas it was higher in one country. Thus, for most countries, factors other than family structure explain the multifaceted MVPA behaviour, supporting the need for a systems approach to promoting PA [<xref ref-type="bibr" rid="pone.0300188.ref073">73</xref>]. The association between living with one versus two parents and VPA varied somewhat across countries, with adolescents in fourteen countries having a lower likelihood of VPA ≥ 4 times/week. The differential associations could partly be explained by region, with a lower likelihood of living with one parent observed in Northern and Eastern Europe. The interaction between family structure and the geographical region became non-significant when controlling for country-level SES, suggesting that differences at country-level SES could largely explain this association.</p>
<p>A similar finding was observed when examining the impact of living with one versus two parents on overweight and obesity in a recent study based on the same sample, with stronger associations detected in the Northern/Western region that, to a large extent, was explained by country-level SES [<xref ref-type="bibr" rid="pone.0300188.ref026">26</xref>]. The current study findings may contribute to explaining the observed influences of one versus two parents on overweight and obesity, as PA is consistently negatively associated with overweight/obesity [<xref ref-type="bibr" rid="pone.0300188.ref001">1</xref>, <xref ref-type="bibr" rid="pone.0300188.ref074">74</xref>]. Although countries with higher country-level SES, like those in the Northern region, tend to have more well-developed family policies and welfare systems, the situation when it comes to financial strain and poverty is still unfavourable for one-parent families, partly because their employment is more likely part-time and based on temporary contracts [<xref ref-type="bibr" rid="pone.0300188.ref044">44</xref>]. A study by Badura and colleagues (2021) found that adolescents from lower SES families and non-nuclear families (consisting of two parents and their child) were less likely to participate in organised activities across nine countries from Western, Central and Northern Europe and Canada with divergent social and socioeconomic contexts [<xref ref-type="bibr" rid="pone.0300188.ref037">37</xref>].</p>
<p>There may also be differences between and within the geographical regions in how sport and PA are organised that co-occur with higher country-level SES. In many countries, organised competitive sports for children and youth is carried out in the context of the school or in combination with club sport. In Nordic countries, however, voluntary competitive sports for children and youth is mostly organised outside the school system [<xref ref-type="bibr" rid="pone.0300188.ref075">75</xref>]. Also, much of the club sports organised for young people in these countries depend somewhat on parental involvement, e.g. as a coach or other voluntary work [<xref ref-type="bibr" rid="pone.0300188.ref038">38</xref>, <xref ref-type="bibr" rid="pone.0300188.ref075">75</xref>]. Lack of time, a more likely challenge in one-parent families, may thus influence the ability to take on such responsibilities and become a barrier to club sport involvement.</p>
<p>In contrast, in Portugal, the sport system is structurally separated into club or school sport [<xref ref-type="bibr" rid="pone.0300188.ref076">76</xref>]. The school sport system where the students can attend freely is divided into internal activities with recreational and competitive sports inside the school and external activities that aim to specialise students in a particular sport and compete against other schools [<xref ref-type="bibr" rid="pone.0300188.ref076">76</xref>]. Still, significant cross-country variations in the extent and nature of school sport systems in Europe have been documented [<xref ref-type="bibr" rid="pone.0300188.ref077">77</xref>]. For instance, in some countries (e.g. France, Poland and Sweden), a participation fee for extracurricular school sport activities is required [<xref ref-type="bibr" rid="pone.0300188.ref077">77</xref>]. In Sweden, low participation rates in extracurricular activities are also explained by a negative attitude towards competition within Swedish schools and easy access to clubs outside of school [<xref ref-type="bibr" rid="pone.0300188.ref078">78</xref>]. Thus, an extracurricular school sport system may reduce differences related to family structure, as it puts less demand on families to facilitate and support PA engagement. Another factor that may account for some cross-country variations is the proximity to attractive arenas for PA and sports for youth. For instance, the Nordic region is the least densely populated in Europe [<xref ref-type="bibr" rid="pone.0300188.ref079">79</xref>], and with sparse settlement, young people will more often depend on their parents for transportation to training facilities.</p>
</sec>
<sec id="sec024">
<title>Implications</title>
<p>Policymakers, the sport sector, and health professionals should know that adolescents’ family context can be complex and potentially affect their involvement in PA, especially leisure time VPA. The present findings suggest that the existing welfare policies do not necessarily eliminate family structure differences. The role of both family support and the structural organisation of youth sports should be addressed in public PA initiatives, and policy actions should support families with limited time and poorer access to PA facilities. Also, as the proportion of children and adolescents living in ONE-parent or stepparent families continues to grow, it is important to monitor PA habits by family structure, together with overall population trends. Lastly, the current study should also be considered from a broader public health perspective, as unfavourable PA levels add to several other negative health behaviours observed among adolescents living in ONE-parent or stepparent families, for example, dietary behaviours, smoking, and substance use [<xref ref-type="bibr" rid="pone.0300188.ref023">23</xref>–<xref ref-type="bibr" rid="pone.0300188.ref025">25</xref>].</p>
</sec>
<sec id="sec025">
<title>Strengths and limitations</title>
<p>There are several strengths and limitations of the study that should be considered. The large sample size gave sufficient statistical power to examine interaction effects related to family structure. The study also controlled for several important covariates. A strength is the use of well-established measures and comparable individual-level data from 40 countries based on comprehensive methodological data collection procedures.</p>
<p>However, the study has some limitations. All data were self-reported, known to have recall and reporting bias [<xref ref-type="bibr" rid="pone.0300188.ref080">80</xref>]. However, most items have been documented to have satisfying validity and reliability [<xref ref-type="bibr" rid="pone.0300188.ref046">46</xref>]. Of note, SES was measured by FAS, an indicator of material affluence [<xref ref-type="bibr" rid="pone.0300188.ref054">54</xref>]. The associations between SES and family structure differences may differ for other SES indicators, as FAS in a Swedish study was only moderately correlated with parental income and weakly correlated with parents’ occupational status [<xref ref-type="bibr" rid="pone.0300188.ref081">81</xref>].</p>
<p>In this study, we lack information on how long the participants lived in their current family structure, the PA motivational climate in the family [<xref ref-type="bibr" rid="pone.0300188.ref016">16</xref>], and other household characteristics (e.g., BMI and PA of the primary caretaker), limiting our ability to study the processes involved. limiting our ability to study the processes involved. In addition, we could not differentiate between those living in a one-parent family with no involvement from the other parent or those part-time or nearly 50/50 with each parent with potentially extensive involvement of both parents. The influence of the school environment facilitation on the amount of PA, which is independent of parental SES, was also not considered. Finally, the study had a cross-sectional design and unobserved sources of the observed association were not accounted for, which makes it difficult to propose any causality.</p>
</sec>
<sec id="sec026" sec-type="conclusions">
<title>Conclusion</title>
<p>As the structure of families is changing in many countries, studying the associations between family structure and PA is important at this time. Pooled data demonstrated that family structure correlated with daily 60 min MVPA and ≥ 4 times/week VPA. Still, cross-country differences in associations between living with one versus two parents and PA highlight the value of collecting comparable cross-national data on adolescent health behaviours and their social contexts. The study findings should be considered in developing policies and programs that aim to facilitate PA, especially in countries where living with one versus two parents was associated with a lower likelihood of PA. More country-specific research is needed to address different types of psychosocial challenges and stress relevant to one-parent families in particular.</p>
</sec>
</sec>
</body>
<back>
<ack>
<p>HBSC is an international study carried out in collaboration with the World Health Organization/Europe WHO/EURO. The authors acknowledge the International coordinator of the 2013/2014 survey, Professor Candace Currie and her team at the University of St. Andrews, Scotland, and the International Data Centre Manager, Professor Oddrun Samdal and her team at the University of Bergen, Norway. We also thank all the participating students, staff and schools that took part in the HBSC survey, as well as all PIs from the countries examined.</p>
</ack>
<ref-list>
<title>References</title>
<ref id="pone.0300188.ref001"><label>1</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Chaput</surname> <given-names>J-P</given-names></name>, <name name-style="western"><surname>Willumsen</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Bull</surname> <given-names>F</given-names></name>, <name name-style="western"><surname>Chou</surname> <given-names>R</given-names></name>, <name name-style="western"><surname>Ekelund</surname> <given-names>U</given-names></name>, <name name-style="western"><surname>Firth</surname> <given-names>J</given-names></name>, <etal>et al</etal>. <article-title>2020 WHO guidelines on physical activity and sedentary behaviour for children and adolescents aged 5–17 years: summary of the evidence</article-title>. <source>International Journal of Behavioral Nutrition and Physical Activity</source>. <year>2020</year>;<volume>17</volume>:<fpage>1</fpage>–<lpage>9</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref002"><label>2</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Guinhouya</surname> <given-names>BC</given-names></name>, <name name-style="western"><surname>Samouda</surname> <given-names>H</given-names></name>, <name name-style="western"><surname>Zitouni</surname> <given-names>D</given-names></name>, <name name-style="western"><surname>Vilhelm</surname> <given-names>C</given-names></name>, <name name-style="western"><surname>Hubert</surname> <given-names>H</given-names></name>. <article-title>Evidence of the influence of physical activity on the metabolic syndrome and/or on insulin resistance in pediatric populations: a systematic review</article-title>. <source>International Journal of Pediatric Obesity</source>. <year>2011</year>;<volume>6</volume>(<issue>5‐6</issue>):<fpage>361</fpage>–<lpage>88</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3109/17477166.2011.605896" xlink:type="simple">10.3109/17477166.2011.605896</ext-link></comment> <object-id pub-id-type="pmid">21851163</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref003"><label>3</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Marques</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Calmeiro</surname> <given-names>L</given-names></name>, <name name-style="western"><surname>Loureiro</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Frasquilho</surname> <given-names>D</given-names></name>, <name name-style="western"><surname>de Matos</surname> <given-names>MG</given-names></name>. <article-title>Health complaints among adolescents: Associations with more screen-based behaviours and less physical activity</article-title>. <source>Journal of adolescence</source>. <year>2015</year>;<volume>44</volume>:<fpage>150</fpage>–<lpage>7</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1016/j.adolescence.2015.07.018" xlink:type="simple">10.1016/j.adolescence.2015.07.018</ext-link></comment> <object-id pub-id-type="pmid">26275746</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref004"><label>4</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Oberste</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Medele</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Javelle</surname> <given-names>F</given-names></name>, <name name-style="western"><surname>Lioba Wunram</surname> <given-names>H</given-names></name>, <name name-style="western"><surname>Walter</surname> <given-names>D</given-names></name>, <name name-style="western"><surname>Bloch</surname> <given-names>W</given-names></name>, <etal>et al</etal>. <article-title>Physical activity for the treatment of adolescent depression: a systematic review and meta-analysis</article-title>. <source>Frontiers in physiology</source>. <year>2020</year>;<volume>11</volume>:<fpage>185</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fphys.2020.00185" xlink:type="simple">10.3389/fphys.2020.00185</ext-link></comment> <object-id pub-id-type="pmid">32265725</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref005"><label>5</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Vancampfort</surname> <given-names>D</given-names></name>, <name name-style="western"><surname>Hallgren</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Firth</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Rosenbaum</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Schuch</surname> <given-names>FB</given-names></name>, <name name-style="western"><surname>Mugisha</surname> <given-names>J</given-names></name>, <etal>et al</etal>. <article-title>Physical activity and suicidal ideation: A systematic review and meta-analysis</article-title>. <source>Journal of affective disorders</source>. <year>2018</year>;<volume>225</volume>:<fpage>438</fpage>–<lpage>48</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1016/j.jad.2017.08.070" xlink:type="simple">10.1016/j.jad.2017.08.070</ext-link></comment> <object-id pub-id-type="pmid">28858658</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref006"><label>6</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Biddle</surname> <given-names>SJ</given-names></name>, <name name-style="western"><surname>Ciaccioni</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Thomas</surname> <given-names>G</given-names></name>, <name name-style="western"><surname>Vergeer</surname> <given-names>I</given-names></name>. <article-title>Physical activity and mental health in children and adolescents: An updated review of reviews and an analysis of causality</article-title>. <source>Psychology of sport and exercise</source>. <year>2019</year>;<volume>42</volume>:<fpage>146</fpage>–<lpage>55</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref007"><label>7</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Marques</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Santos</surname> <given-names>DA</given-names></name>, <name name-style="western"><surname>Hillman</surname> <given-names>CH</given-names></name>, <name name-style="western"><surname>Sardinha</surname> <given-names>LB</given-names></name>. <article-title>How does academic achievement relate to cardiorespiratory fitness, self-reported physical activity and objectively reported physical activity: a systematic review in children and adolescents aged 6–18 years</article-title>. <source>British Journal of Sports Medicine</source>. <year>2018</year>;<volume>52</volume>(<issue>16</issue>):<fpage>1039</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1136/bjsports-2016-097361" xlink:type="simple">10.1136/bjsports-2016-097361</ext-link></comment> <object-id pub-id-type="pmid">29032365</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref008"><label>8</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Inchley</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Currie</surname> <given-names>D</given-names></name>, <name name-style="western"><surname>Budisavljevic</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Torsheim</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Jåstad</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Cosma</surname> <given-names>A</given-names></name>, <etal>et al</etal>. <article-title>Spotlight on adolescent health and well-being. Findings from the 2017/2018 Health Behaviour in School-aged Children (HBSC) survey in Europe and Canada</article-title>. <source>International report</source>. <year>2020</year>;<volume>1</volume>.</mixed-citation></ref>
<ref id="pone.0300188.ref009"><label>9</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Guthold</surname> <given-names>R</given-names></name>, <name name-style="western"><surname>Stevens</surname> <given-names>GA</given-names></name>, <name name-style="western"><surname>Riley</surname> <given-names>LM</given-names></name>, <name name-style="western"><surname>Bull</surname> <given-names>FC</given-names></name>. <article-title>Global trends in insufficient physical activity among adolescents: a pooled analysis of 298 population-based surveys with 1· 6 million participants</article-title>. <source>The Lancet Child &amp; Adolescent Health</source>. <year>2020</year>;<volume>4</volume>(<issue>1</issue>):<fpage>23</fpage>–<lpage>35</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref010"><label>10</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Sallis</surname> <given-names>JF</given-names></name>, <name name-style="western"><surname>Owen</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Fotheringham</surname> <given-names>MJ</given-names></name>. <article-title>Behavioral epidemiology: a systematic framework to classify phases of research on health promotion and disease prevention</article-title>. <source>Annals of behavioral medicine</source>. <year>2000</year>;<volume>22</volume>(<issue>4</issue>):<fpage>294</fpage>–<lpage>8</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1007/BF02895665" xlink:type="simple">10.1007/BF02895665</ext-link></comment> <object-id pub-id-type="pmid">11253440</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref011"><label>11</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Sallis</surname> <given-names>JF</given-names></name>, <name name-style="western"><surname>Owen</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Fisher</surname> <given-names>E</given-names></name>. <article-title>Ecological models of health behavior</article-title>. <source>Health behavior: Theory, research, and practice</source>. <year>2015</year>;<volume>5</volume>(<issue>43–64</issue>).</mixed-citation></ref>
<ref id="pone.0300188.ref012"><label>12</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Blazo</surname> <given-names>JA</given-names></name>, <name name-style="western"><surname>Smith</surname> <given-names>AL</given-names></name>. <article-title>A systematic review of siblings and physical activity experiences</article-title>. <source>International Review of Sport and Exercise Psychology</source>. <year>2018</year>;<volume>11</volume>(<issue>1</issue>):<fpage>122</fpage>–<lpage>59</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref013"><label>13</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Biddle</surname> <given-names>SJ</given-names></name>, <name name-style="western"><surname>Atkin</surname> <given-names>AJ</given-names></name>, <name name-style="western"><surname>Cavill</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Foster</surname> <given-names>C</given-names></name>. <article-title>Correlates of physical activity in youth: a review of quantitative systematic reviews</article-title>. <source>International review of sport and exercise psychology</source>. <year>2011</year>;<volume>4</volume>(<issue>1</issue>):<fpage>25</fpage>–<lpage>49</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref014"><label>14</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Gustafson</surname> <given-names>SL</given-names></name>, <name name-style="western"><surname>Rhodes</surname> <given-names>RE</given-names></name>. <article-title>Parental correlates of physical activity in children and early adolescents</article-title>. <source>Sports medicine</source>. <year>2006</year>;<volume>36</volume>(<issue>1</issue>):<fpage>79</fpage>–<lpage>97</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.2165/00007256-200636010-00006" xlink:type="simple">10.2165/00007256-200636010-00006</ext-link></comment> <object-id pub-id-type="pmid">16445312</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref015"><label>15</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Fredricks</surname> <given-names>JA</given-names></name>, <name name-style="western"><surname>Eccles</surname> <given-names>JS</given-names></name>. <article-title>Family socialization, gender, and sport motivation and involvement</article-title>. <source>Journal of sport and Exercise Psychology</source>. <year>2005</year>;<volume>27</volume>(<issue>1</issue>):<fpage>3</fpage>–<lpage>31</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref016"><label>16</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>O’Rourke</surname> <given-names>DJ</given-names></name>, <name name-style="western"><surname>Smith</surname> <given-names>RE</given-names></name>, <name name-style="western"><surname>Smoll</surname> <given-names>FL</given-names></name>, <name name-style="western"><surname>Cumming</surname> <given-names>SP</given-names></name>. <article-title>Parent-initiated motivational climate and young athletes’ intrinsic-extrinsic motivation: Cross-sectional and longitudinal relations</article-title>. <source>Journal of Child and Adolescent Behavior</source>. <year>2013</year>;<volume>1</volume>(<issue>2</issue>):<fpage>109</fpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref017"><label>17</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Simonen</surname> <given-names>RL</given-names></name>, <name name-style="western"><surname>Perusse</surname> <given-names>L</given-names></name>, <name name-style="western"><surname>Rankinen</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Rice</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Rao</surname> <given-names>D</given-names></name>, <name name-style="western"><surname>Bouchard</surname> <given-names>C</given-names></name>. <article-title>Familial aggregation of physical activity levels in the Quebec Family Study</article-title>. <source>Medicine &amp; Science in Sports &amp; Exercise</source>. <year>2002</year>;<volume>34</volume>(<issue>7</issue>):<fpage>1137</fpage>–<lpage>42</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref018"><label>18</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Yang</surname> <given-names>XL</given-names></name>, <name name-style="western"><surname>Telama</surname> <given-names>R</given-names></name>, <name name-style="western"><surname>Laakso</surname> <given-names>L</given-names></name>. <article-title>Parents’ physical activity, socioeconomic status and education as predictors of physical activity and sport among children and youths-A 12-year follow-up study</article-title>. <source>International review for the sociology of sport</source>. <year>1996</year>;<volume>31</volume>(<issue>3</issue>):<fpage>273</fpage>–<lpage>91</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref019"><label>19</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Musić Milanović</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Buoncristiano</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Križan</surname> <given-names>H</given-names></name>, <name name-style="western"><surname>Rathmes</surname> <given-names>G</given-names></name>, <name name-style="western"><surname>Williams</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Hyska</surname> <given-names>J</given-names></name>, <etal>et al</etal>. <article-title>Socioeconomic disparities in physical activity, sedentary behavior and sleep patterns among 6‐to 9‐year‐old children from 24 countries in the WHO European region</article-title>. <source>Obesity Reviews</source>. <year>2021</year>:<fpage>e13209</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1111/obr.13209" xlink:type="simple">10.1111/obr.13209</ext-link></comment> <object-id pub-id-type="pmid">34235843</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref020"><label>20</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Pearce</surname> <given-names>LD</given-names></name>, <name name-style="western"><surname>Hayward</surname> <given-names>GM</given-names></name>, <name name-style="western"><surname>Chassin</surname> <given-names>L</given-names></name>, <name name-style="western"><surname>Curran</surname> <given-names>PJ</given-names></name>. <article-title>The increasing diversity and complexity of family structures for adolescents</article-title>. <source>Journal of Research on Adolescence</source>. <year>2018</year>;<volume>28</volume>(<issue>3</issue>):<fpage>591</fpage>–<lpage>608</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1111/jora.12391" xlink:type="simple">10.1111/jora.12391</ext-link></comment> <object-id pub-id-type="pmid">30197489</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref021"><label>21</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Steinbach</surname> <given-names>A</given-names></name>. <article-title>Children’s and parents’ well‐being in joint physical custody: A literature review</article-title>. <source>Family Process</source>. <year>2019</year>;<volume>58</volume>(<issue>2</issue>):<fpage>353</fpage>–<lpage>69</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1111/famp.12372" xlink:type="simple">10.1111/famp.12372</ext-link></comment> <object-id pub-id-type="pmid">29963700</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref022"><label>22</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Stahlmann</surname> <given-names>K</given-names></name>, <name name-style="western"><surname>Hebestreit</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>DeHenauw</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Hunsberger</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Kaprio</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Lissner</surname> <given-names>L</given-names></name>, <etal>et al</etal>. <article-title>A cross-sectional study of obesogenic behaviours and family rules according to family structure in European children</article-title>. <source>International Journal of Behavioral Nutrition and Physical Activity</source>. <year>2020</year>;<volume>17</volume>(<issue>1</issue>):<fpage>1</fpage>–<lpage>12</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref023"><label>23</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Troxel</surname> <given-names>WM</given-names></name>, <name name-style="western"><surname>Lee</surname> <given-names>L</given-names></name>, <name name-style="western"><surname>Hall</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Matthews</surname> <given-names>KA</given-names></name>. <article-title>Single-parent family structure and sleep problems in black and white adolescents</article-title>. <source>Sleep medicine</source>. <year>2014</year>;<volume>15</volume>(<issue>2</issue>):<fpage>255</fpage>–<lpage>61</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1016/j.sleep.2013.10.012" xlink:type="simple">10.1016/j.sleep.2013.10.012</ext-link></comment> <object-id pub-id-type="pmid">24424100</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref024"><label>24</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Zaborskis</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Grincaitė</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Kavaliauskienė</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Tesler</surname> <given-names>R</given-names></name>. <article-title>Family structure and affluence in adolescent eating behaviour: a cross-national study in forty-one countries</article-title>. <source>Public Health Nutrition</source>. <year>2021</year>;<volume>24</volume>(<issue>9</issue>):<fpage>2521</fpage>–<lpage>32</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1017/S1368980020003584" xlink:type="simple">10.1017/S1368980020003584</ext-link></comment> <object-id pub-id-type="pmid">33106205</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref025"><label>25</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Fismen</surname> <given-names>A-S</given-names></name>, <name name-style="western"><surname>Smith</surname> <given-names>ORF</given-names></name>, <name name-style="western"><surname>Samdal</surname> <given-names>O</given-names></name>, <name name-style="western"><surname>Helleve</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Haug</surname> <given-names>E</given-names></name>. <article-title>Associations between family structure and adolescents’ food habits</article-title>. <source>Public Health Nutrition</source>. <year>2022</year>;<volume>25</volume>(<issue>3</issue>):<fpage>702</fpage>–<lpage>9</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1017/S1368980020004334" xlink:type="simple">10.1017/S1368980020004334</ext-link></comment> <object-id pub-id-type="pmid">33109279</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref026"><label>26</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Fismen</surname> <given-names>A-S</given-names></name>, <name name-style="western"><surname>Smith</surname> <given-names>ORF</given-names></name>, <name name-style="western"><surname>Helleve</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Haug</surname> <given-names>E</given-names></name>, <name name-style="western"><surname>Chatelan</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Kelly</surname> <given-names>C</given-names></name>, <etal>et al</etal>. <article-title>Cross-national variation in the association between family structure and overweight and obesity: Findings from the Health Behaviour in School-aged children (HBSC) study</article-title>. <source>SSM-Population Health</source>. <year>2022</year>;<volume>19</volume>:<fpage>101127</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1016/j.ssmph.2022.101127" xlink:type="simple">10.1016/j.ssmph.2022.101127</ext-link></comment> <object-id pub-id-type="pmid">35677220</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref027"><label>27</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Bagley</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Salmon</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Crawford</surname> <given-names>D</given-names></name>. <article-title>Family structure and children’s television viewing and physical activity</article-title>. <source>Medicine and Science in Sports and Exercise</source>. <year>2006</year>;<volume>38</volume>(<issue>5</issue>):<fpage>910</fpage>–<lpage>8</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1249/01.mss.0000218132.68268.f4" xlink:type="simple">10.1249/01.mss.0000218132.68268.f4</ext-link></comment> <object-id pub-id-type="pmid">16672845</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref028"><label>28</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Hesketh</surname> <given-names>K</given-names></name>, <name name-style="western"><surname>Graham</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Waters</surname> <given-names>E</given-names></name>. <article-title>Children’s after-school activity: associations with weight status and family circumstance</article-title>. <source>Pediatric exercise science</source>. <year>2008</year>;<volume>20</volume>(<issue>1</issue>):<fpage>84</fpage>–<lpage>94</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1123/pes.20.1.84" xlink:type="simple">10.1123/pes.20.1.84</ext-link></comment> <object-id pub-id-type="pmid">18364537</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref029"><label>29</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>O’Loughlin</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Paradis</surname> <given-names>G</given-names></name>, <name name-style="western"><surname>Kishchuk</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Barnett</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Renaud</surname> <given-names>L</given-names></name>. <article-title>Prevalence and correlates of physical activity behaviors among elementary schoolchildren in multiethnic, low income, inner-city neighborhoods in Montreal, Canada</article-title>. <source>Annals of Epidemiology</source>. <year>1999</year>;<volume>9</volume>(<issue>7</issue>):<fpage>397</fpage>–<lpage>407</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1016/s1047-2797%2899%2900030-7" xlink:type="simple">10.1016/s1047-2797(99)00030-7</ext-link></comment> <object-id pub-id-type="pmid">10501407</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref030"><label>30</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Gorely</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Atkin</surname> <given-names>AJ</given-names></name>, <name name-style="western"><surname>Biddle</surname> <given-names>SJ</given-names></name>, <name name-style="western"><surname>Marshall</surname> <given-names>SJ</given-names></name>. <article-title>Family circumstance, sedentary behaviour and physical activity in adolescents living in England: Project STIL</article-title>. <source>International Journal of Behavioral Nutrition and Physical Activity</source>. <year>2009</year>;<volume>6</volume>(<issue>1</issue>):<fpage>1</fpage>–<lpage>8</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1186/1479-5868-6-33" xlink:type="simple">10.1186/1479-5868-6-33</ext-link></comment> <object-id pub-id-type="pmid">19519913</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref031"><label>31</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Sallis</surname> <given-names>JF</given-names></name>, <name name-style="western"><surname>Prochaska</surname> <given-names>JJ</given-names></name>, <name name-style="western"><surname>Taylor</surname> <given-names>WC</given-names></name>, <name name-style="western"><surname>Hill</surname> <given-names>JO</given-names></name>, <name name-style="western"><surname>Geraci</surname> <given-names>JC</given-names></name>. <article-title>Correlates of physical activity in a national sample of girls and boys in grades 4 through 12</article-title>. <source>Health psychology</source>. <year>1999</year>;<volume>18</volume>(<issue>4</issue>):<fpage>410</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1037//0278-6133.18.4.410" xlink:type="simple">10.1037//0278-6133.18.4.410</ext-link></comment> <object-id pub-id-type="pmid">10431943</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref032"><label>32</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>McMillan</surname> <given-names>R</given-names></name>, <name name-style="western"><surname>McIsaac</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Janssen</surname> <given-names>I</given-names></name>. <article-title>Family structure as a correlate of organized sport participation among youth</article-title>. <source>PloS one</source>. <year>2016</year>;<volume>11</volume>(<issue>2</issue>):<fpage>e0147403</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1371/journal.pone.0147403" xlink:type="simple">10.1371/journal.pone.0147403</ext-link></comment> <object-id pub-id-type="pmid">26863108</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref033"><label>33</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Tremblay</surname> <given-names>MS</given-names></name>, <name name-style="western"><surname>Willms</surname> <given-names>JD</given-names></name>. <article-title>Is the Canadian childhood obesity epidemic related to physical inactivity?</article-title> <source>International journal of obesity</source>. <year>2003</year>;<volume>27</volume>(<issue>9</issue>):<fpage>1100</fpage>–<lpage>5</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1038/sj.ijo.0802376" xlink:type="simple">10.1038/sj.ijo.0802376</ext-link></comment> <object-id pub-id-type="pmid">12917717</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref034"><label>34</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Toftegaard‐Støckel</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Nielsen</surname> <given-names>G</given-names></name>, <name name-style="western"><surname>Ibsen</surname> <given-names>B</given-names></name>, <name name-style="western"><surname>Andersen</surname> <given-names>LB</given-names></name>. <article-title>Parental, socio and cultural factors associated with adolescents’ sports participation in four Danish municipalities</article-title>. <source>Scandinavian journal of medicine &amp; science in sports</source>. <year>2011</year>;<volume>21</volume>(<issue>4</issue>):<fpage>606</fpage>–<lpage>11</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1111/j.1600-0838.2010.01093.x" xlink:type="simple">10.1111/j.1600-0838.2010.01093.x</ext-link></comment> <object-id pub-id-type="pmid">20459468</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref035"><label>35</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Quarmby</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Dagkas</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Bridge</surname> <given-names>M</given-names></name>. <article-title>Associations between children’s physical activities, sedentary behaviours and family structure: a sequential mixed methods approach</article-title>. <source>Health education research</source>. <year>2011</year>;<volume>26</volume>(<issue>1</issue>):<fpage>63</fpage>–<lpage>76</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1093/her/cyq071" xlink:type="simple">10.1093/her/cyq071</ext-link></comment> <object-id pub-id-type="pmid">21059801</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref036"><label>36</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>McVeigh</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Norris</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>De Wet</surname> <given-names>T</given-names></name>. <article-title>The relationship between socio‐economic status and physical activity patterns in South African children</article-title>. <source>Acta Paediatrica</source>. <year>2004</year>;<volume>93</volume>(<issue>7</issue>):<fpage>982</fpage>–<lpage>8</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1111/j.1651-2227.2004.tb02699.x" xlink:type="simple">10.1111/j.1651-2227.2004.tb02699.x</ext-link></comment> <object-id pub-id-type="pmid">15303817</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref037"><label>37</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Badura</surname> <given-names>P</given-names></name>, <name name-style="western"><surname>Hamrik</surname> <given-names>Z</given-names></name>, <name name-style="western"><surname>Dierckens</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Gobiņa</surname> <given-names>I</given-names></name>, <name name-style="western"><surname>Malinowska-Cieślik</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Furstova</surname> <given-names>J</given-names></name>, <etal>et al</etal>. <article-title>After the bell: adolescents’ organised leisure-time activities and well-being in the context of social and socioeconomic inequalities</article-title>. <source>J epidemiol community health</source>. <year>2021</year>;<volume>75</volume>(<issue>7</issue>):<fpage>628</fpage>–<lpage>36</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1136/jech-2020-215319" xlink:type="simple">10.1136/jech-2020-215319</ext-link></comment> <object-id pub-id-type="pmid">33402394</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref038"><label>38</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Langøy</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Smith</surname> <given-names>OR</given-names></name>, <name name-style="western"><surname>Wold</surname> <given-names>B</given-names></name>, <name name-style="western"><surname>Samdal</surname> <given-names>O</given-names></name>, <name name-style="western"><surname>Haug</surname> <given-names>EM</given-names></name>. <article-title>Associations between family structure and young people’s physical activity and screen time behaviors</article-title>. <source>BMC Public Health</source>. <year>2019</year>;<volume>19</volume>(<issue>1</issue>):<fpage>1</fpage>–<lpage>10</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref039"><label>39</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Duncan</surname> <given-names>SC</given-names></name>, <name name-style="western"><surname>Duncan</surname> <given-names>TE</given-names></name>, <name name-style="western"><surname>Strycker</surname> <given-names>LA</given-names></name>, <name name-style="western"><surname>Chaumeton</surname> <given-names>NR</given-names></name>. <article-title>A multilevel analysis of sibling physical activity</article-title>. <source>Journal of Sport and Exercise Psychology</source>. <year>2004</year>;<volume>26</volume>(<issue>1</issue>):<fpage>57</fpage>–<lpage>68</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref040"><label>40</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Lindquist</surname> <given-names>CH</given-names></name>, <name name-style="western"><surname>Reynolds</surname> <given-names>KD</given-names></name>, <name name-style="western"><surname>Goran</surname> <given-names>MI</given-names></name>. <article-title>Sociocultural determinants of physical activity among children</article-title>. <source>Preventive medicine</source>. <year>1999</year>;<volume>29</volume>(<issue>4</issue>):<fpage>305</fpage>–<lpage>12</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1006/pmed.1999.0546" xlink:type="simple">10.1006/pmed.1999.0546</ext-link></comment> <object-id pub-id-type="pmid">10547056</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref041"><label>41</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Wang</surname> <given-names>L</given-names></name>, <name name-style="western"><surname>Qi</surname> <given-names>J</given-names></name>. <article-title>Association between family structure and physical activity of Chinese adolescents</article-title>. <source>BioMed research international</source>. <year>2016</year>;<volume>2016</volume>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1155/2016/4278682" xlink:type="simple">10.1155/2016/4278682</ext-link></comment> <object-id pub-id-type="pmid">27123446</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref042"><label>42</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Sallis</surname> <given-names>JF</given-names></name>, <name name-style="western"><surname>Alcaraz</surname> <given-names>JE</given-names></name>, <name name-style="western"><surname>McKenzie</surname> <given-names>TL</given-names></name>, <name name-style="western"><surname>Hovell</surname> <given-names>MF</given-names></name>, <name name-style="western"><surname>Kolody</surname> <given-names>B</given-names></name>, <name name-style="western"><surname>Nader</surname> <given-names>PR</given-names></name>. <article-title>Parental behavior in relation to physical activity and fitness in 9-year-old children</article-title>. <source>American Journal of Diseases of Children</source>. <year>1992</year>;<volume>146</volume>(<issue>11</issue>):<fpage>1383</fpage>–<lpage>8</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1001/archpedi.1992.02160230141035" xlink:type="simple">10.1001/archpedi.1992.02160230141035</ext-link></comment> <object-id pub-id-type="pmid">1415081</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref043"><label>43</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Hoffmann</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Sander</surname> <given-names>L</given-names></name>, <name name-style="western"><surname>Wachtler</surname> <given-names>B</given-names></name>, <name name-style="western"><surname>Blume</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Schneider</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Herke</surname> <given-names>M</given-names></name>, <etal>et al</etal>. <article-title>Moderating or mediating effects of family characteristics on socioeconomic inequalities in child health in high-income countries—a scoping review</article-title>. <source>BMC Public Health</source>. <year>2022</year>;<volume>22</volume>(<issue>1</issue>):<fpage>1</fpage>–<lpage>14</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref044"><label>44</label><mixed-citation publication-type="other" xlink:type="simple">Nieuwnhuis R. The situation of single parents in the EU. Brussels: European Parliament 2020.</mixed-citation></ref>
<ref id="pone.0300188.ref045"><label>45</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Inchley</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Currie</surname> <given-names>D</given-names></name>. <article-title>Growing up unequal: gender and socioeconomic differences in young people’s health and well-being</article-title>. <source>Health Behaviour in School-aged Children (HBSC) study: international report from the 2013/2014 survey: World Health Organization</source>; <year>2016</year>.</mixed-citation></ref>
<ref id="pone.0300188.ref046"><label>46</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Currie</surname> <given-names>C</given-names></name>, <name name-style="western"><surname>Inchley</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Molcho</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Lenzi</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Veselska</surname> <given-names>Z</given-names></name>, <name name-style="western"><surname>Wild</surname> <given-names>F</given-names></name>. <source>Health Behaviour in School-aged Children (HBSC) study protocol: background, methodology and mandatory items for the 2013/14 survey</source>. <year>2014</year>.</mixed-citation></ref>
<ref id="pone.0300188.ref047"><label>47</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Prochaska</surname> <given-names>JJ</given-names></name>, <name name-style="western"><surname>Sallis</surname> <given-names>JF</given-names></name>, <name name-style="western"><surname>Long</surname> <given-names>B</given-names></name>. <article-title>A physical activity screening measure for use with adolescents in primary care</article-title>. <source>Archives of pediatrics &amp; adolescent medicine</source>. <year>2001</year>;<volume>155</volume>(<issue>5</issue>):<fpage>554</fpage>–<lpage>9</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1001/archpedi.155.5.554" xlink:type="simple">10.1001/archpedi.155.5.554</ext-link></comment> <object-id pub-id-type="pmid">11343497</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref048"><label>48</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Biddle</surname> <given-names>SJ</given-names></name>, <name name-style="western"><surname>Gorely</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Pearson</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Bull</surname> <given-names>FC</given-names></name>. <article-title>An assessment of self-reported physical activity instruments in young people for population surveillance: Project ALPHA</article-title>. <source>International Journal of Behavioral Nutrition and Physical Activity</source>. <year>2011</year>;<volume>8</volume>(<issue>1</issue>):<fpage>1</fpage>–<lpage>9</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1186/1479-5868-8-1" xlink:type="simple">10.1186/1479-5868-8-1</ext-link></comment> <object-id pub-id-type="pmid">21194492</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref049"><label>49</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Ng</surname> <given-names>K</given-names></name>, <name name-style="western"><surname>Hämylä</surname> <given-names>R</given-names></name>, <name name-style="western"><surname>Tynjälä</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Villberg</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Tammelin</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Kannas</surname> <given-names>L</given-names></name>, <etal>et al</etal>. <article-title>Test-retest reliability of adolescents’ self-reported physical activity item in two consecutive surveys</article-title>. <source>Archives of Public Health</source>. <year>2019</year>;<volume>77</volume>(<issue>1</issue>):<fpage>1</fpage>–<lpage>8</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1186/s13690-019-0335-3" xlink:type="simple">10.1186/s13690-019-0335-3</ext-link></comment> <object-id pub-id-type="pmid">30891238</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref050"><label>50</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Ridgers</surname> <given-names>ND</given-names></name>, <name name-style="western"><surname>Timperio</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Crawford</surname> <given-names>D</given-names></name>, <name name-style="western"><surname>Salmon</surname> <given-names>J</given-names></name>. <article-title>Validity of a brief self-report instrument for assessing compliance with physical activity guidelines amongst adolescents</article-title>. <source>Journal of Science and Medicine in Sport</source>. <year>2012</year>;<volume>15</volume>(<issue>2</issue>):<fpage>136</fpage>–<lpage>41</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1016/j.jsams.2011.09.003" xlink:type="simple">10.1016/j.jsams.2011.09.003</ext-link></comment> <object-id pub-id-type="pmid">22051688</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref051"><label>51</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Hardie Murphy</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Rowe</surname> <given-names>DA</given-names></name>, <name name-style="western"><surname>Belton</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Woods</surname> <given-names>CB</given-names></name>. <article-title>Validity of a two-item physical activity questionnaire for assessing attainment of physical activity guidelines in youth</article-title>. <source>BMC Public Health</source>. <year>2015</year>;<volume>15</volume>(<issue>1</issue>):<fpage>1</fpage>–<lpage>8</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1186/s12889-015-2418-6" xlink:type="simple">10.1186/s12889-015-2418-6</ext-link></comment> <object-id pub-id-type="pmid">26498827</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref052"><label>52</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Booth</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Okely</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Chey</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Bauman</surname> <given-names>A</given-names></name>. <article-title>The reliability and validity of the physical activity questions in the WHO health behaviour in schoolchildren (HBSC) survey: a population study</article-title>. <source>British journal of sports medicine</source>. <year>2001</year>;<volume>35</volume>(<issue>4</issue>):<fpage>263</fpage>–<lpage>7</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1136/bjsm.35.4.263" xlink:type="simple">10.1136/bjsm.35.4.263</ext-link></comment> <object-id pub-id-type="pmid">11477024</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref053"><label>53</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Rangul</surname> <given-names>V</given-names></name>, <name name-style="western"><surname>Holmen</surname> <given-names>TL</given-names></name>, <name name-style="western"><surname>Kurtze</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Cuypers</surname> <given-names>K</given-names></name>, <name name-style="western"><surname>Midthjell</surname> <given-names>K</given-names></name>. <article-title>Reliability and validity of two frequently used self-administered physical activity questionnaires in adolescents</article-title>. <source>BMC medical research methodology</source>. <year>2008</year>;<volume>8</volume>(<issue>1</issue>):<fpage>1</fpage>–<lpage>10</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1186/1471-2288-8-47" xlink:type="simple">10.1186/1471-2288-8-47</ext-link></comment> <object-id pub-id-type="pmid">18627632</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref054"><label>54</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Hartley</surname> <given-names>JE</given-names></name>, <name name-style="western"><surname>Levin</surname> <given-names>K</given-names></name>, <name name-style="western"><surname>Currie</surname> <given-names>C</given-names></name>. <article-title>A new version of the HBSC family affluence scale-FAS III: Scottish qualitative findings from the international FAS development study</article-title>. <source>Child indicators research</source>. <year>2016</year>;<volume>9</volume>(<issue>1</issue>):<fpage>233</fpage>–<lpage>45</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref055"><label>55</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Hobza</surname> <given-names>V</given-names></name>, <name name-style="western"><surname>Hamrik</surname> <given-names>Z</given-names></name>, <name name-style="western"><surname>Bucksch</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>De Clercq</surname> <given-names>B</given-names></name>. <article-title>The family affluence scale as an indicator for socioeconomic status: Validation on regional income differences in the Czech Republic</article-title>. <source>International journal of environmental research and public health</source>. <year>2017</year>;<volume>14</volume>(<issue>12</issue>):<fpage>1540</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3390/ijerph14121540" xlink:type="simple">10.3390/ijerph14121540</ext-link></comment> <object-id pub-id-type="pmid">29292773</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref056"><label>56</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Boyce</surname> <given-names>W</given-names></name>, <name name-style="western"><surname>Torsheim</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Currie</surname> <given-names>C</given-names></name>, <name name-style="western"><surname>Zambon</surname> <given-names>A</given-names></name>. <article-title>The family affluence scale as a measure of national wealth: validation of an adolescent self-report measure</article-title>. <source>Social indicators research</source>. <year>2006</year>;<volume>78</volume>:<fpage>473</fpage>–<lpage>87</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref057"><label>57</label><mixed-citation publication-type="other" xlink:type="simple">European Union. EU vocabularies. EuroVoc Thesaurus. Europe. The Publications Office of the European Union 7206 Europe—EU Vocabularies 2020.</mixed-citation></ref>
<ref id="pone.0300188.ref058"><label>58</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Möhring</surname> <given-names>K.</given-names></name> <article-title>The fixed effects as an alternative to multilevel analysis for cross-national analyses</article-title>. <source>GK Soclife, WorNing paper</source>. <year>2012</year>;<volume>16</volume>.</mixed-citation></ref>
<ref id="pone.0300188.ref059"><label>59</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Pearson</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Braithwaite</surname> <given-names>R</given-names></name>, <name name-style="western"><surname>Biddle</surname> <given-names>SJ</given-names></name>, <name name-style="western"><surname>van Sluijs</surname> <given-names>EM</given-names></name>, <name name-style="western"><surname>Atkin</surname> <given-names>AJ</given-names></name>. <article-title>Associations between sedentary behaviour and physical activity in children and adolescents: a meta‐analysis</article-title>. <source>Obesity reviews</source>. <year>2014</year>;<volume>15</volume>(<issue>8</issue>):<fpage>666</fpage>–<lpage>75</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1111/obr.12188" xlink:type="simple">10.1111/obr.12188</ext-link></comment> <object-id pub-id-type="pmid">24844784</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref060"><label>60</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Sigmundová</surname> <given-names>D</given-names></name>, <name name-style="western"><surname>Sigmund</surname> <given-names>E</given-names></name>, <name name-style="western"><surname>Tesler</surname> <given-names>R</given-names></name>, <name name-style="western"><surname>Ng</surname> <given-names>KW</given-names></name>, <name name-style="western"><surname>Hamrik</surname> <given-names>Z</given-names></name>, <name name-style="western"><surname>Mathisen</surname> <given-names>FKS</given-names></name>, <etal>et al</etal>. <article-title>Vigorous physical activity in relation to family affluence: Time trends in Europe and North America</article-title>. <source>International journal of public health</source>. <year>2019</year>;<volume>64</volume>:<fpage>1049</fpage>–<lpage>58</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1007/s00038-019-01271-8" xlink:type="simple">10.1007/s00038-019-01271-8</ext-link></comment> <object-id pub-id-type="pmid">31278436</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref061"><label>61</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Mathisen</surname> <given-names>FK</given-names></name>, <name name-style="western"><surname>Kokko</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Tynjälä</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Torsheim</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Wold</surname> <given-names>B</given-names></name>. <article-title>Leisure‐time physical activity and participation in organized sports: Changes from 1985 to 2014 in Finland and Norway</article-title>. <source>Scandinavian journal of medicine &amp; science in sports</source>. <year>2019</year>;<volume>29</volume>(<issue>8</issue>):<fpage>1232</fpage>–<lpage>42</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref062"><label>62</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Mooses</surname> <given-names>K</given-names></name>, <name name-style="western"><surname>Kull</surname> <given-names>M</given-names></name>. <article-title>The participation in organised sport doubles the odds of meeting physical activity recommendations in 7–12-year-old children</article-title>. <source>European journal of sport science</source>. <year>2020</year>;<volume>20</volume>(<issue>4</issue>):<fpage>563</fpage>–<lpage>9</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1080/17461391.2019.1645887" xlink:type="simple">10.1080/17461391.2019.1645887</ext-link></comment> <object-id pub-id-type="pmid">31314683</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref063"><label>63</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Quarmby</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Dagkas</surname> <given-names>S</given-names></name>. <article-title>Children’s engagement in leisure time physical activity: exploring family structure as a determinant</article-title>. <source>Leisure Studies</source>. <year>2010</year>;<volume>29</volume>(<issue>1</issue>):<fpage>53</fpage>–<lpage>66</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref064"><label>64</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>O’Brien</surname> <given-names>W</given-names></name>, <name name-style="western"><surname>Coppinger</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Hogan</surname> <given-names>I</given-names></name>, <name name-style="western"><surname>Belton</surname> <given-names>S</given-names></name>, <name name-style="western"><surname>Murphy</surname> <given-names>MH</given-names></name>, <name name-style="western"><surname>Powell</surname> <given-names>C</given-names></name>, <etal>et al</etal>. <article-title>The association of family, friends, and teacher support with girls’ sport and physical activity on the island of Ireland</article-title>. <source>Journal of physical activity and health</source>. <year>2021</year>;<volume>18</volume>(<issue>8</issue>):<fpage>929</fpage>–<lpage>36</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1123/jpah.2020-0386" xlink:type="simple">10.1123/jpah.2020-0386</ext-link></comment> <object-id pub-id-type="pmid">34098528</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref065"><label>65</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Strandbu</surname> <given-names>Å</given-names></name>, <name name-style="western"><surname>Bakken</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Stefansen</surname> <given-names>K</given-names></name>. <article-title>The continued importance of family sport culture for sport participation during the teenage years</article-title>. <source>Sport, Education and Society</source>. <year>2020</year>;<volume>25</volume>(<issue>8</issue>):<fpage>931</fpage>–<lpage>45</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref066"><label>66</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Herke</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Knöchelmann</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Richter</surname> <given-names>M</given-names></name>. <article-title>Health and well-being of adolescents in different family structures in Germany and the importance of family climate</article-title>. <source>International journal of environmental research and public health</source>. <year>2020</year>;<volume>17</volume>(<issue>18</issue>):<fpage>6470</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3390/ijerph17186470" xlink:type="simple">10.3390/ijerph17186470</ext-link></comment> <object-id pub-id-type="pmid">32899489</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref067"><label>67</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Manning</surname> <given-names>WD</given-names></name>, <name name-style="western"><surname>Brown</surname> <given-names>S</given-names></name>. <article-title>Children’s economic well‐being in married and cohabiting parent families</article-title>. <source>Journal of Marriage and Family</source>. <year>2006</year>;<volume>68</volume>(<issue>2</issue>):<fpage>345</fpage>–<lpage>62</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref068"><label>68</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Fuemmeler</surname> <given-names>BF</given-names></name>, <name name-style="western"><surname>Anderson</surname> <given-names>CB</given-names></name>, <name name-style="western"><surname>Mâsse</surname> <given-names>LC</given-names></name>. <article-title>Parent-child relationship of directly measured physical activity</article-title>. <source>International Journal of Behavioral Nutrition and Physical Activity</source>. <year>2011</year>;<volume>8</volume>:<fpage>1</fpage>–<lpage>9</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref069"><label>69</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Breivik</surname> <given-names>K</given-names></name>, <name name-style="western"><surname>Olweus</surname> <given-names>D</given-names></name>. <article-title>Adolescent’s adjustment in four post-divorce family structures: Single mother, stepfather, joint physical custody and single father families</article-title>. <source>Journal of Divorce &amp; Remarriage</source>. <year>2006</year>;<volume>44</volume>(<issue>3–4</issue>):<fpage>99</fpage>–<lpage>124</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref070"><label>70</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Kracht</surname> <given-names>CL</given-names></name>, <name name-style="western"><surname>Sisson</surname> <given-names>SB</given-names></name>. <article-title>Sibling influence on children’s objectively measured physical activity: A meta-analysis and systematic review</article-title>. <source>BMJ open sport &amp; exercise medicine</source>. <year>2018</year>;<volume>4</volume>(<issue>1</issue>):<fpage>e000405</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1136/bmjsem-2018-000405" xlink:type="simple">10.1136/bmjsem-2018-000405</ext-link></comment> <object-id pub-id-type="pmid">30364499</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref071"><label>71</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Chambers</surname> <given-names>SA</given-names></name>, <name name-style="western"><surname>Rowa-Dewar</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Radley</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Dobbie</surname> <given-names>F</given-names></name>. <article-title>A systematic review of grandparents’ influence on grandchildren’s cancer risk factors</article-title>. <source>Plos one</source>. <year>2017</year>;<volume>12</volume>(<issue>11</issue>):<fpage>e0185420</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1371/journal.pone.0185420" xlink:type="simple">10.1371/journal.pone.0185420</ext-link></comment> <object-id pub-id-type="pmid">29135979</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref072"><label>72</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Xie</surname> <given-names>H</given-names></name>, <name name-style="western"><surname>Ainsworth</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Caldwell</surname> <given-names>L</given-names></name>. <article-title>Grandparent (s) coresidence and physical activity/screen time among Latino children in the United States</article-title>. <source>Families, Systems, &amp; Health</source>. <year>2021</year>;<volume>39</volume>(<issue>2</issue>):<fpage>282</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1037/fsh0000601" xlink:type="simple">10.1037/fsh0000601</ext-link></comment> <object-id pub-id-type="pmid">34410771</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref073"><label>73</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Rutter</surname> <given-names>H</given-names></name>, <name name-style="western"><surname>Cavill</surname> <given-names>N</given-names></name>, <name name-style="western"><surname>Bauman</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Bull</surname> <given-names>F</given-names></name>. <article-title>Systems approaches to global and national physical activity plans</article-title>. <source>Bulletin of the World Health Organization</source>. <year>2019</year>;<volume>97</volume>(<issue>2</issue>):<fpage>162</fpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.2471/BLT.18.220533" xlink:type="simple">10.2471/BLT.18.220533</ext-link></comment> <object-id pub-id-type="pmid">30728623</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref074"><label>74</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Haug</surname> <given-names>E</given-names></name>, <name name-style="western"><surname>Rasmussen</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Samdal</surname> <given-names>O</given-names></name>, <name name-style="western"><surname>Iannotti</surname> <given-names>R</given-names></name>, <name name-style="western"><surname>Kelly</surname> <given-names>C</given-names></name>, <name name-style="western"><surname>Borraccino</surname> <given-names>A</given-names></name>, <etal>et al</etal>. <article-title>Overweight in school-aged children and its relationship with demographic and lifestyle factors: results from the WHO-Collaborative Health Behaviour in School-aged Children (HBSC) study</article-title>. <source>International journal of public health</source>. <year>2009</year>;<volume>54</volume>:<fpage>167</fpage>–<lpage>79</lpage>. <comment>doi: <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1007/s00038-009-5408-6" xlink:type="simple">10.1007/s00038-009-5408-6</ext-link></comment> <object-id pub-id-type="pmid">19618111</object-id></mixed-citation></ref>
<ref id="pone.0300188.ref075"><label>75</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Bairner</surname> <given-names>A.</given-names></name> <article-title>What’s Scandinavian about Scandinavian sport?</article-title> <source>Sport in society</source>. <year>2010</year>;<volume>13</volume>(<issue>4</issue>):<fpage>734</fpage>–<lpage>43</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref076"><label>76</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Marques</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Martins</surname> <given-names>J</given-names></name>, <name name-style="western"><surname>Santos</surname> <given-names>F</given-names></name>, <name name-style="western"><surname>Sarmento</surname> <given-names>H</given-names></name>, <name name-style="western"><surname>da Costa</surname> <given-names>FC</given-names></name>. <article-title>Correlates of school sport participation: A cross-sectional study in urban Portuguese students. Science &amp;</article-title> <source>Sports</source>. <year>2014</year>;<volume>29</volume>(<issue>4</issue>):<fpage>e31</fpage>–<lpage>e8</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref077"><label>77</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Marques</surname> <given-names>A</given-names></name>, <name name-style="western"><surname>Holzweg</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Scheuer</surname> <given-names>C</given-names></name>, <name name-style="western"><surname>Repond</surname> <given-names>R-M</given-names></name>, <name name-style="western"><surname>Correia</surname> <given-names>C</given-names></name>, <name name-style="western"><surname>Santo</surname> <given-names>RE</given-names></name>, <etal>et al</etal>. <article-title>Extracurricular sports in European schools: A descriptive study</article-title>. <source>International Sports Studies</source>. <year>2014</year>;<volume>36</volume>(<issue>1</issue>):<fpage>63</fpage>–<lpage>70</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref078"><label>78</label><mixed-citation publication-type="book" xlink:type="simple"><name name-style="western"><surname>Annerstedt</surname> <given-names>C</given-names></name>, <name name-style="western"><surname>Eriksson</surname> <given-names>S</given-names></name>., <name name-style="western"><surname>Patriksson</surname> <given-names>G</given-names></name>., &amp; <name name-style="western"><surname>Strahlman</surname> <given-names>O</given-names></name>. <chapter-title>Physical Education and Education through Sport in Sweden</chapter-title>. In: <name name-style="western"><surname>Hardman</surname> <given-names>GKK</given-names></name>, editor. <source>Physical Education and Sport Education in the European Union Paris</source>: <publisher-name>Éditions Revue</publisher-name>.; <year>2008</year>. p. <fpage>422</fpage>–<lpage>36</lpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref079"><label>79</label><mixed-citation publication-type="other" xlink:type="simple">European Health Information Gateway. Average population density per km2.: World Health Organization,; 2023 <ext-link ext-link-type="uri" xlink:href="https://gateway.euro.who.int/en/indicators/hfa_27-0160-average-population-density-per-km2/visualizations/#id=18834%26;tab=table" xlink:type="simple">https://gateway.euro.who.int/en/indicators/hfa_27-0160-average-population-density-per-km2/visualizations/#id=18834&amp;tab=table</ext-link></mixed-citation></ref>
<ref id="pone.0300188.ref080"><label>80</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Nigg</surname> <given-names>CR</given-names></name>, <name name-style="western"><surname>Fuchs</surname> <given-names>R</given-names></name>, <name name-style="western"><surname>Gerber</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Jekauc</surname> <given-names>D</given-names></name>, <name name-style="western"><surname>Koch</surname> <given-names>T</given-names></name>, <name name-style="western"><surname>Krell-Roesch</surname> <given-names>J</given-names></name>, <etal>et al</etal>. <article-title>Assessing physical activity through questionnaires—A consensus of best practices and future directions</article-title>. <source>Psychology of Sport and Exercise</source>. <year>2020</year>;<volume>50</volume>:<fpage>101715</fpage>.</mixed-citation></ref>
<ref id="pone.0300188.ref081"><label>81</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Corell</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Chen</surname> <given-names>Y</given-names></name>, <name name-style="western"><surname>Friberg</surname> <given-names>P</given-names></name>, <name name-style="western"><surname>Petzold</surname> <given-names>M</given-names></name>, <name name-style="western"><surname>Löfstedt</surname> <given-names>P</given-names></name>. <article-title>Does the family affluence scale reflect actual parental earned income, level of education and occupational status? A validation study using register data in Sweden</article-title>. <source>BMC Public Health</source>. <year>2021</year>;<volume>21</volume>(<issue>1</issue>):<fpage>1</fpage>–<lpage>11</lpage>.</mixed-citation></ref>
</ref-list>
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<named-content content-type="letter-date">12 Oct 2023</named-content>
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<p><!-- <div> -->PONE-D-23-23392<!-- </div> --><!-- <div> -->Family Structure and the association with physical activity – findings from 40 Countries participating in the Health Behaviour in School-aged Children (HBSC) Study<!-- </div> --><!-- <div> -->PLOS ONE</p>
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<p>Reviewer #1: Dear Authors,</p>
<p>this is a well-written manuscript that needs only a few minor changes.</p>
<p>There are several places in the paper where you could use the abbreviation for physical activity (PA) instead of the full name.</p>
<p>Figure 2 and Figure 3 are a bit fuzzy and should be adjusted.</p>
<p>Please state the novelty and practical implications of your study.</p>
<p>Reviewer #2: Thank you for the opportunity to review this manuscript on family structure associated with physical activity in school-aged children. Please find my comments below.</p>
<p>My major concerns are as follows: (1) Not all factors associated with PA were controlled for; for example, caregiver’s BMI and PA could largely affect child’s BMI and PA, which is not accounted for in this paper; (2) a family structure could signal other issues in the family, leading to omitted variable bias on the family structure variable; (3) the countries in the sample are extremely varied and have very different SES levels and community supports for family and PA (including built environment, sports facilities, school curriculum) – it is possible that fixed effects are too limited to account for these differences; (4) ORs in a model with a non-rare outcome over-inflates the relative risk and should not be used.</p>
<p>More detailed comments are below.</p>
<p>I wonder if variance decomposition could be used to see how different family structures contribute to the variation in PA (compared to other variables).</p>
<p>Line 149: If having parent + stepparent was included as a separate binary covariate in the regression, the model assumes that one can have one parent and parent+stepparent at the same time (which is impossible). I wonder if “parent + step parent” should be included as a fourth category in the main covariate (one parent, 2 parents, parent + step parent, no parents). This could also be done in a separate model.</p>
<p>Line 170: Would it be possible to treat MVPA and VPA as a continuous variable as a supplemental analysis? Dichotomizing a variable leads to some loss of information, and ORs often represent an inflated measure of risk.</p>
<p>Line 180: Odds ratios (as mentioned above) represent an inflated measure of risk. While logit models are appropriate for use with binary variables, odds ratios can only be used to approximate relative risk when the outcome is rare. In the descriptive statistics, the outcome ranges from 9% to ~30%, making this not a rare outcome. In this case, authors should estimate relative risk instead of using odds ratios. Given that authors used Stata, it is very straightforward to obtain measures of both absolute difference in risk and relative risk from any model, including logit. Please refer to the following publications for methods:</p>
<p>Kleinman, Lawrence C., and Edward C. Norton. "What's the risk? A simple approach for estimating adjusted risk measures from nonlinear models including logistic regression." Health services research 44.1 (2009): 288-302.</p>
<p>Norton, Edward C., Morgen M. Miller, and Lawrence C. Kleinman. "Computing adjusted risk ratios and risk differences in Stata." The Stata Journal 13.3 (2013): 492-509.</p>
<p>Line 198: I wonder if the authors have attempted to test other ways of controlling for country differences. The sample includes extremely different countries with different supports for families and PA. It would make sense to test for both fixed and random effects, as well as looking at certain regions separately. I would like to see some evidence that a fixed effects model is the best model for this type of sample.</p>
<p>Line 195: Why wasn’t the country-level SES used in the models? What about other household characteristics (such as age, gender, BMI, PA of primary caretaker, BMI of the child, etc)?</p>
<p>Line 195: It would be helpful to clearly list all models with all of their covariates in each model; otherwise, it is hard to understand what covariates were included and how – from the Statistics paragraph as written. Perhaps include this as a supplemental table if there is no space in the text.</p>
<p>**********</p>
<p><!-- <font color="black"> -->6. PLOS authors have the option to publish the peer review history of their article (<ext-link ext-link-type="uri" xlink:href="https://journals.plos.org/plosone/s/editorial-and-peer-review-process#loc-peer-review-history" xlink:type="simple">what does this mean?</ext-link>). If published, this will include your full peer review and any attached files.</p>
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<p><bold>Do you want your identity to be public for this peer review?</bold> For information about this choice, including consent withdrawal, please see our <ext-link ext-link-type="uri" xlink:href="https://www.plos.org/privacy-policy" xlink:type="simple">Privacy Policy</ext-link>.<!-- </font> --></p>
<p>Reviewer #1: No</p>
<p>Reviewer #2: No</p>
<p>**********</p>
<p>[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]</p>
<p>While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, <ext-link ext-link-type="uri" xlink:href="https://pacev2.apexcovantage.com/" xlink:type="simple">https://pacev2.apexcovantage.com/</ext-link>. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at <email xlink:type="simple">figures@plos.org</email>. Please note that Supporting Information files do not need this step.</p>
</body>
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<sub-article article-type="author-comment" id="pone.0300188.r002">
<front-stub>
<article-id pub-id-type="doi">10.1371/journal.pone.0300188.r002</article-id>
<title-group>
<article-title>Author response to Decision Letter 0</article-title>
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<p>
<named-content content-type="author-response-date">7 Dec 2023</named-content>
</p>
<p>Dear ACADEMIC EDITOR: </p>
<p>We want to thank the reviewers for their constructive and positive feedback about the manuscript, which we believe has improved the quality of our paper. We have addressed all comments and provided a point-by-point response. To clarify, reviewers’ comments are in bold font, and, where appropriate, we have inserted the revised text in blue, with new text highlighted. Please see our rebuttal letter and updated manuscript.</p>
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<p>Submitted filename: <named-content content-type="submitted-filename">Response  to Reviewers.docx</named-content></p>
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<sub-article article-type="aggregated-review-documents" id="pone.0300188.r003" specific-use="decision-letter">
<front-stub>
<article-id pub-id-type="doi">10.1371/journal.pone.0300188.r003</article-id>
<title-group>
<article-title>Decision Letter 1</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name name-style="western">
<surname>Jaafar</surname>
<given-names>Zulkarnain</given-names>
</name>
<role>Academic Editor</role>
</contrib>
</contrib-group>
<permissions>
<copyright-year>2024</copyright-year>
<copyright-holder>Zulkarnain Jaafar</copyright-holder>
<license xlink:href="http://creativecommons.org/licenses/by/4.0/">
<license-p>This is an open access article distributed under the terms of the <ext-link ext-link-type="uri" xlink:href="http://creativecommons.org/licenses/by/4.0/" xlink:type="simple">Creative Commons Attribution License</ext-link>, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.</license-p>
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<p>
<named-content content-type="letter-date">23 Feb 2024</named-content>
</p>
<p>Family Structure and the association with physical activity – findings from 40 Countries participating in the Health Behaviour in School-aged Children (HBSC) Study</p>
<p>PONE-D-23-23392R1</p>
<p>Dear Dr.Melingen Haug,</p>
<p>We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.</p>
<p>Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.</p>
<p>An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at <ext-link ext-link-type="uri" xlink:href="http://www.editorialmanager.com/pone/" xlink:type="simple">http://www.editorialmanager.com/pone/</ext-link>, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at <email xlink:type="simple">authorbilling@plos.org</email>.</p>
<p>If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact <email xlink:type="simple">onepress@plos.org</email>.</p>
<p>Kind regards,</p>
<p>Zulkarnain Jaafar</p>
<p>Academic Editor</p>
<p>PLOS ONE</p>
<p>Additional Editor Comments (optional):</p>
<p>Reviewers' comments:</p>
<p>Reviewer's Responses to Questions</p>
<p><!-- <font color="black"> --><bold>Comments to the Author</bold></p>
<p>1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.<!-- </font> --></p>
<p>Reviewer #3: All comments have been addressed</p>
<p>**********</p>
<p><!-- <font color="black"> -->2. Is the manuscript technically sound, and do the data support the conclusions?</p>
<p>The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. <!-- </font> --></p>
<p>Reviewer #3: Yes</p>
<p>**********</p>
<p><!-- <font color="black"> -->3. Has the statistical analysis been performed appropriately and rigorously? <!-- </font> --></p>
<p>Reviewer #3: I Don't Know</p>
<p>**********</p>
<p><!-- <font color="black"> -->4. Have the authors made all data underlying the findings in their manuscript fully available?</p>
<p>The <ext-link ext-link-type="uri" xlink:href="http://www.plosone.org/static/policies.action#sharing" xlink:type="simple">PLOS Data policy</ext-link> requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.<!-- </font> --></p>
<p>Reviewer #3: Yes</p>
<p>**********</p>
<p><!-- <font color="black"> -->5. Is the manuscript presented in an intelligible fashion and written in standard English?</p>
<p>PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.<!-- </font> --></p>
<p>Reviewer #3: Yes</p>
<p>**********</p>
<p><!-- <font color="black"> -->6. Review Comments to the Author</p>
<p>Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)<!-- </font> --></p>
<p>Reviewer #3: The topic of this research article is interesting. and I can see that the authors have made an effort to address all the comments of previous authors.</p>
<p>**********</p>
<p><!-- <font color="black"> -->7. PLOS authors have the option to publish the peer review history of their article (<ext-link ext-link-type="uri" xlink:href="https://journals.plos.org/plosone/s/editorial-and-peer-review-process#loc-peer-review-history" xlink:type="simple">what does this mean?</ext-link>). If published, this will include your full peer review and any attached files.</p>
<p>If you choose “no”, your identity will remain anonymous but your review may still be made public.</p>
<p><bold>Do you want your identity to be public for this peer review?</bold> For information about this choice, including consent withdrawal, please see our <ext-link ext-link-type="uri" xlink:href="https://www.plos.org/privacy-policy" xlink:type="simple">Privacy Policy</ext-link>.<!-- </font> --></p>
<p>Reviewer #3: No</p>
<p>**********</p>
</body>
</sub-article>
<sub-article article-type="editor-report" id="pone.0300188.r004" specific-use="acceptance-letter">
<front-stub>
<article-id pub-id-type="doi">10.1371/journal.pone.0300188.r004</article-id>
<title-group>
<article-title>Acceptance letter</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name name-style="western">
<surname>Jaafar</surname>
<given-names>Zulkarnain</given-names>
</name>
<role>Academic Editor</role>
</contrib>
</contrib-group>
<permissions>
<copyright-year>2024</copyright-year>
<copyright-holder>Zulkarnain Jaafar</copyright-holder>
<license xlink:href="http://creativecommons.org/licenses/by/4.0/">
<license-p>This is an open access article distributed under the terms of the <ext-link ext-link-type="uri" xlink:href="http://creativecommons.org/licenses/by/4.0/" xlink:type="simple">Creative Commons Attribution License</ext-link>, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.</license-p>
</license>
</permissions>
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<body>
<p>
<named-content content-type="letter-date">4 Apr 2024</named-content>
</p>
<p>PONE-D-23-23392R1 </p>
<p>PLOS ONE</p>
<p>Dear Dr.  Haug, </p>
<p>I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now being handed over to our production team.</p>
<p>At this stage, our production department will prepare your paper for publication. This includes ensuring the following:</p>
<p>* All references, tables, and figures are properly cited</p>
<p>* All relevant supporting information is included in the manuscript submission,</p>
<p>* There are no issues that prevent the paper from being properly typeset</p>
<p>If revisions are needed, the production department will contact you directly to resolve them. If no revisions are needed, you will receive an email when the publication date has been set. At this time, we do not offer pre-publication proofs to authors during production of the accepted work. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few weeks to review your paper and let you know the next and final steps. </p>
<p>Lastly, if your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact <email xlink:type="simple">onepress@plos.org</email>.</p>
<p>If we can help with anything else, please email us at <email xlink:type="simple">customercare@plos.org</email>.</p>
<p>Thank you for submitting your work to PLOS ONE and supporting open access. </p>
<p>Kind regards, </p>
<p>PLOS ONE Editorial Office Staff</p>
<p>on behalf of</p>
<p>Dr. Zulkarnain Jaafar </p>
<p>Academic Editor</p>
<p>PLOS ONE</p>
</body>
</sub-article>
</article>