PLoS ONE plos plosone PLOS ONE 1932-6203 Public Library of Science San Francisco, CA USA 10.1371/journal.pone.0299023 PONE-D-23-34165 Research Article Medicine and health sciencesVascular medicineBlood pressure Research and analysis methodsResearch designSurvey researchQuestionnaires Medicine and health sciencesVascular medicineBlood pressureHypertension Physical sciencesChemistryChemical compoundsChlorides Medicine and health sciencesCardiologyArrhythmia Research and analysis methodsMathematical and statistical techniquesStatistical methodsRegression analysis Physical sciencesMathematicsStatisticsStatistical methodsRegression analysis People and placesPopulation groupingsAge groupsAdultsElderly Biology and life sciencesPsychologyPsychometrics Social sciencesPsychologyPsychometrics Night-time hot spring bathing is associated with improved blood pressure control: A mobile application and paper questionnaire study Association between night-time hot springs bathing and blood pressure https://orcid.org/0000-0002-6143-7906 Yamasaki Satoshi Conceptualization Data curation Formal analysis Funding acquisition Investigation Methodology Project administration Resources Software Supervision Validation Visualization Writing – original draft Writing – review & editing 1 2 * Kashiwado Yusuke Conceptualization Methodology Project administration Writing – review & editing 1 Maeda Toyoki Supervision Writing – review & editing 1 Horiuchi Takahiko Supervision Writing – review & editing 1 Department of Internal Medicine, Kyushu University Beppu Hospital, Beppu, Japan Department of Hematology and Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan Samala Venkata Vikramaditya Editor Dartmouth Health, UNITED STATES

NO authors have competing interests.

 * E-mail: yamas009@gmail.com 1 11 2024 2024 19 11 e0299023 23 10 2023 3 2 2024 2024 Yamasaki et al This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Hot spring bathing practice helps to manage hypertension. However, the details of the relationship between hot spring bathing and hypertension remain unknown. Older people are thought to be less adept than younger people at using digital devices such as mobile applications. Whether mobile application questionnaires, which have been increasing in recent years, can be used by older people is unclear. To address the knowledge gap regarding the management of older patients with hypertension, we prospectively evaluated mobile application and paper questionnaires regarding night-time hot spring bathing in respondents who had a choice of which to use. Changes in blood pressure because of hot spring bathing were evaluated. To investigate the effects of night-time hot spring bathing on blood pressure in adults, 1116 volunteers at 14 institutions in Beppu completed the study, including 562 in the mobile application questionnaire group and 556 in the paper questionnaire group. A total of 474 of 477 (99.3%) respondents aged ≥65 years used paper questionnaires. There was a significantly lower drop in both systolic and diastolic blood pressure after using hot springs in respondents aged ≥65 years than in respondents aged <65 years (p<0.001). An age ≥65 years, hypertension with medication, arrhythmia, depression, and using a chloride hot spring were independently and significantly associated with a lower drop in both systolic and diastolic blood pressure after night-time hot spring bathing (p<0.001). Night-time hot spring bathing was significantly associated with reduced blood pressure in older adults (p<0.001). Extending this research by examining how psychosocial factors in respondents aged ≥65 years influence preferences for mobile and paper questionnaires may be beneficial, and further investigation is warranted.

 The author(s) received no specific funding for this work. Data Availability All relevant data are within the manuscript and its Supporting information files. Introduction

The prevalence of hypertension in patients aged ≥20 years is high worldwide [1]. One study showed that the control of blood pressure to a systolic pressure of <130 mmHg and a diastolic pressure of <80 mmHg after antihypertensive drug therapy was achieved by 54%, 50%, 46%, and 33% of patients aged 20–54 years, 55–64 years, 65–74 years, and ≥75 years, respectively [2]. The treatment of hypertension should involve lifestyle modifications, such as dietary salt restriction [3], weight loss [4], better diet [5], exercise [6], limited alcohol intake [1], reduced smoking [7], reduced consumption of coffee and tea [8], more sleep [9], and hot spring bathing in older patients [10]. However, the details of the relationship between hot spring bathing and hypertension remain unknown.

In Japan, there is a long history of habitual daily bathing, which involves hot bathing rather than showering. In areas where there are hot springs, including Beppu, which contains the highest concentration of hot spring sources worldwide and has 9 of the 10 hot spring types, people appear to habitually prefer bathing in hot springs. Hot spring bathing, which has balneotherapeutic effects according to the hot spring type as reported by the Japanese Ministry of the Environment [11], is more effective for raising core body temperature than hot tap-water bathing.

Medical questionnaires, including those on hypertension [12], are widely administered in numerous medical fields and are used by many specialists. Using paper questionnaires is important to assess the effect of hot spring bathing on health-related issues, but previous questionnaire studies on this topic have been limited to small geographical areas, such as a single city [13]. The benefits of mobile application questionnaires include ease of use, immediate electronic storage of results and automatic scoring, avoidance of secondary data entry errors, and easier follow-up of records over time [14]. Additionally, there has been positive feedback on the use of mobile application questionnaires (which included informed consent procedures) to assess quality of life [15], medical education [16], interventions, diagnostics, and questionnaire completion [17].

To address the knowledge gap regarding the management of older patients with hypertension, we prospectively evaluated the use of mobile application and paper questionnaires regarding hot spring bathing and evaluated reductions in blood pressure owing to hot spring bathing. The primary objective of this study was to identify the type of questionnaires selected by adults aged ≥65 years. We also measured variables that could affect blood pressure, such as demographics, medical history, and concomitant medications. We performed univariate and multivariate regression analyses to examine the correlations between these variables. We identified which variables were dependent variables on the basis of our prespecified hypothesis of an inverse correlation between night-time hot spring bathing and blood pressure, as reported in a previous cross-sectional study [10].

 Materials and methods Study population

In this study, we developed a mobile application questionnaire from Neo Marketing Inc., Tokyo, Japan, and a paper (S1 Table) questionnaire. When completing electronic questionnaires on a mobile phone, an interface from Neo Marketing Inc. is sent to the mobile application questionnaires, while another interface from the mobile phone is sent to data storage in Neo Marketing Inc. This system enables adults to complete mobile application questionnaires directly on their mobile phone while enabling questionnaire researchers to quickly obtain all necessary questionnaires through the mobile application and analysis. The study population included 1116 adults aged ≥18 years who were using night-time hot springs at 14 institutions in Beppu (6 members of the Beppu Tourist Hotel Association, 7 hot springs organized by Beppu City, and our institution). Each participating institution has similar methods and equipment to automatically measure blood pressure immediately before and after hot spring bathing.

We included 434 men and 684 women aged 22–94 years who met the inclusion criteria, provided consent, and were enrolled in this study between 26 June 2023 and 30 September 2023. The inclusion criteria were men and women aged at least 18 years who could read and who used night-time hot springs. In this study, the primary end point was that 80% of the respondents were able to complete the required questions. If 85% of respondents were able to complete the questions, the α error was 0.05, the power was 0.80, and n = 365 participants were required. Therefore, the required number of respondents was 400 for each form and application.

Initially, we used a questionnaire using a mobile application, but the respondents could also use a paper questionnaire if they preferred. This selection between mobile and paper questionnaires, which was based on gender, age, and disease history, was used for further analysis of the data. All the data were collected and double-checked for accuracy by two separate research assistants. We examined the following variables: gender; age; hypertension with or without medication; and lifetime disease history, including arrhythmia, stroke, gout, diabetes mellitus, hyperlipidemia, renal disease, and chronic hepatitis, which are associated with a lower prevalence of hypertension in our former study [10]. Informed consent for study participation was obtained by providing the respondents with information on mobile or paper questionnaires. The study was performed in accordance with the institutional guidelines and the principles of the Declaration of Helsinki. The protocol was approved by the institutional review board of Kyushu University Hospital, Japan (No. 22346–00).

 Statistical methods

The prespecified primary analyses of adult preference for a mobile phone or a paper form of the questionnaire used the chi-square test to determine whether the proportion of adults who considered a questionnaire by mobile phone to be the same, better, or much better than a paper version was significantly >50%. Similarly, adult preferences were analyzed in stratified groups on the basis of gender, age (≥65 vs. <65 years), a history of disease, and type of hot spring as defined by the Japan Spa Association (https://www.spa.or.jp/en/spring-quality/; e.g., a “chloride spring” may include sodium chloride, calcium chloride, and magnesium chloride springs, depending on the main ingredients of the cation). We analyzed the frequencies and descriptive statistics of the variables. We excluded respondents if they had missing data for at least one of the covariates. Intergroup differences in categorical variables are expressed as the number and percentage. The chi-square test was used to examine the relationships between categorical variables.

Univariate and multivariate regression analyses were conducted to determine the associations between the variables and a drop in systolic or diastolic blood pressure after night-time hot spring bathing. Covariates that were significant at p<0.05 in the univariate regression analysis were included in the multivariate regression analysis. We prospectively calculated the coefficient and 95% confidence intervals of the effect of a change in systolic and diastolic blood pressure before and after using night-time hot springs using the multivariate regression model. A p value <0.05 was considered statistically significant. All analyses were conducted using EZR (Saitama Medical Center, Saitama, Japan; http://www.jichi.ac.jp/saitama-sct/SaitamaHP.files/statmedEN.html) [18], which is a graphical user interface for R version 2.13.0 (www.r-project.org), and a modified version of R Commander version 1.6–3 designed to add statistical functions.

 Results

The baseline characteristics of the respondents who used night-time hot springs are shown in Table 1. The median (range) age of the respondents who used night-time hot springs in the mobile application and paper questionnaire groups was 48 (22–86) and 79 (60–94) years, respectively. The respondents in the mobile application questionnaire group were younger than those in the paper questionnaire group (p<0.001).

10.1371/journal.pone.0299023.t001 Characteristics of the survey respondents.
Mobile Paper
Characteristic n = 562 n = 556 p
Gender, n (%) Male 158 (28.1) 276 (49.6) <0.001
Female 404 (71.9) 280 (50.4)
Median age (range), years 48 (22–86) 79 (60–94) <0.001
  ≥65 years, n (%) 3 (0.5) 474 (85.3) <0.001
Disease history, n (%)
 Hypertension with medication 288 (51.2) 452 (81.3) <0.001
 Hypertension without medication 271 (48.2) 84 (15.1) <0.001
 Cancer 2 (0.4) 102 (18.3) <0.001
  Acute myocardial infarction and angina 3 (0.5) 105 (18.9) <0.001
  Arrhythmia 3 (0.5) 94 (16.9) <0.001
  Stroke 0 102 (18.3) -
  Gout 5 (0.9) 51 (9.2) <0.001
  Diabetes mellitus 17 (3.0) 254 (45.7) <0.001
  Hyperlipidemia 112 (19.9) 220 (39.6) <0.001
  Renal disease 3 (0.5) 153 (27.5) <0.001
  Depression 391 (69.6) 187 (33.6) <0.001
  Collagen disease 1 (0.2) 0 -
Hot spring bathing, n (%)
 Hot spring type
  Simple 98 (17.4) 72 (12.9) <0.001
  Chloride 464 (82.6) 484 (87.1) 0.044
 Time
  19:00 to 20:00 307 (54.6) 457 (82.2) <0.001
  20:00 to 21:00 215 (38.3) 53 (9.5)
  21:00 to 22:00 34 (6.0) 46 (8.3)
  22:00 or 23:00 6 (1.1) 0
Median (range) BP before bathing, mmHg
  Systolic BP 156 (150–159) 154 (140–159) <0.001
  Diastolic BP 93 (87–94) 94 (75–98) <0.001
Median (range) BP after bathing, mmHg
  Systolic BP 145 (112–147) 126 (112–149) <0.001
  Diastolic BP 85 (65–89) 75 (64–88) <0.001
Median (range) drop in BP after bathing, mmHg
  Systolic BP 11 (9–44) 28 (3–47) <0.001
  Diastolic BP 8 (1–26) 17 (3–31) <0.001

The p values were obtained using the chi-square test.

BP, blood pressure.

To evaluate the association between age (≥65 vs. <65 years old) and a drop in systolic or diastolic blood pressure, we compared the drop in systolic (median: 27 vs. 11 mmHg, range: 3–47 vs. 7–36 mmHg, respectively) and diastolic (median: 17 vs. 8 mmHg, range: 1–31 vs. 1–26 mmHg, respectively) blood pressure after using a night-time hot spring (Fig 1a and 1b, respectively). The drop in both systolic and diastolic blood pressure was significantly lower in respondents aged ≥65 years than in respondents aged <65 years (p<0.001). No complications, side effects, or adverse events were reported from the 14 participating institutions during this study.

10.1371/journal.pone.0299023.g001 <p>a. Drop in systolic blood pressure after night-time hot spring bathing. b. Drop in diastolic blood pressure after night-time hot spring bathing.</p> </caption> <graphic mimetype="image" position="float" xlink:href="info:doi/10.1371/journal.pone.0299023.g001" xlink:type="simple"/> </fig> <p>In the multivariate regression analysis, male gender (<italic>p</italic><0.001), age ≥65 years (<italic>p</italic><0.001), a disease history including hypertension with medication (<italic>p</italic><0.001), hypertension without medication (<italic>p</italic> = 0.007), arrhythmia (<italic>p</italic><0.001), gout (<italic>p</italic><0.001), and depression (<italic>p</italic><0.001), and using a chloride hot spring (<italic>p</italic><0.001) were significantly associated with a drop in systolic blood pressure after night-time hot spring bathing (<xref ref-type="table" rid="pone.0299023.t002">Table 2</xref>). An age ≥65 years (<italic>p</italic><0.001), a disease history including hypertension with medication (<italic>p</italic><0.001), arrhythmia (<italic>p</italic><0.001), and depression (<italic>p</italic><0.001), and using a chloride hot spring (<italic>p</italic><0.001) were significantly associated with a drop in diastolic blood pressure after night-time hot spring bathing (<xref ref-type="table" rid="pone.0299023.t003">Table 3</xref>).</p> <table-wrap id="pone.0299023.t002" position="float"> <object-id pub-id-type="doi">10.1371/journal.pone.0299023.t002</object-id> <label>Table 2</label> <caption><title>Univariate and multivariate regression analyses of variables affecting the drop in systolic blood pressure after night-time hot spring bathing.
Univariate Multivariate
Parameter Variable Coefficient 95% CI s.e. p Coefficient 95% CI s.e. p
Gender Male vs. Female 2.113 0.975, 3.251 0.580 <0.001 2.098 0.960, 3.237 0.580 <0.001
Age ≥65 years vs. <65 years 12.697 11.465, 13.929 0.627 <0.001 13.103 11.960, 14.245 0.582 <0.001
Disease history Hypertension with medication 6.215 3.117, 9.313 1.578 <0.001 6.060 2.966, 9.154 1.577 <0.001
Hypertension without medication 4.381 1.214, 7.547 1.613 0.006 4.319 1.151, 7.487 1.614 0.007
Cancer −0.342 −2.137, 1.452 0.914 0.708
Acute myocardial infarction and angina −12.041 −15.107, −8.976 1.562 <0.001 −10.722 −13.412, −8.033 1.370 <0.001
Arrhythmia 11.861 9.379, 14.343 1.265 <0.001 10.961 8.678, 13.244 1.163 <0.001
Gout 6.595 3.135, 10.055 1.763 <0.001 5.577 2.384, 8.770 1.627 <0.001
Diabetes mellitus −5.008 −6.394, −3.622 0.706 <0.001 −5.210 −6.566, −3.854 0.691 <0.001
Hyperlipidemia −1.746 −2.891, −0.600 0.583 0.002 −1.537 −2.597, −0.477 0.540 0.004
Renal disease −1.457 −3.065, 0.150 0.819 0.075
Depression 3.697 2.562, 4.832 0.578 <0.001 3.638 2.518, 4.758 0.570 <0.001
Hot spring type Chloride vs. Simple 3.760 2.546, 4.974 0.618 <0.001 3.872 2.663, 5.080 0.615 <0.001

s.e., standard error; CI, confidence interval.

Univariate or multivariate competing event statistics analyzed using a regression model were applied to a reduction in systolic blood pressure after night-time hot spring bathing. Covariates significant at p<0.05 in the univariate analysis were included in the multivariate analysis.

 10.1371/journal.pone.0299023.t003 Univariate and multivariate regression analyses of variables affecting the drop in diastolic blood pressure after night-time hot spring bathing.
Univariable Multivariable
Parameter Variable Coefficient 95% CI s.e. p Coefficient 95% CI s.e. p
Gender Male vs. Female −0.185 −0.803, 0.432 0.315 0.556
Age ≥65 years vs.<65 years 5.366 4.697, 6.035 0.341 <0.001 5.377 4.713, 6.042 0.338 <0.001
Disease history Hypertension with medication 2.585 0.902, 4.268 0.857 0.002 1.455 0.912, 1.997 0.276 <0.001
Hypertension without medication 1.147 −0.572, 2.867 0.876 0.190
Cancer −2.216 −3.191, −1.240 0.496 <0.001 −1.971 −2.908, −1.035 0.477 <0.001
Acute myocardial infarction and angina −7.351 −9.016, −5.685 0.848 <0.001 −6.361 −7.499, −5.223 0.579 <0.001
Arrhythmia 10.021 8.672, 11.369 0.687 <0.001 9.474 8.322, 10.627 0.587 <0.001
Gout 1.716 −0.1633, 3.595 0.957 0.073
Diabetes mellitus −6.876 −7.629, −6.124 0.383 <0.001 −7.089 −7.809, −6.368 0.367 <0.001
Hyperlipidemia −2.861 −3.483, −2.239 0.317 <0.001 −2.791 −3.396, −2.186 0.308 <0.001
Renal disease −3.422 −4.295, −2.548 0.445 <0.001 −3.206 −4.046, −2.365 0.428 <0.001
Depression 1.478 0.862, 2.095 0.314 <0.001 1.464 0.941, 1.987 0.266 <0.001
Hot spring type Chloride vs. Simple 2.016 1.357, 2.676 0.336 <0.001 2.087 1.431, 2.743 0.334 <0.001

s.e., standard error; CI, confidence interval.

Univariate or multivariate competing event statistics analyzed using a regression model were applied to diastolic blood pressure reduction after night-time hot spring bathing. Covariates significant at p<0.05 in the univariate analysis were included in the multivariate analysis.

In the multivariate regression analysis, a disease history, including acute myocardial infarction and angina (p<0.001), diabetes mellitus (p<0.001), and hyperlipidemia (p = 0.004), was inversely associated with a drop in systolic blood pressure after night-time hot spring bathing (Table 2). A disease history, including cancer (p<0.001), acute myocardial infarction and angina (p<0.001), diabetes mellitus (p<0.001), hyperlipidemia (p<0.001), and renal disease (p<0.001), was inversely associated with a drop in diastolic blood pressure after night-time hot spring bathing (Table 3).

 Discussion

This study showed that 99.3% of respondents aged ≥65 years used paper questionnaires. There was a significantly lower drop in both systolic and diastolic blood pressure after using hot springs in respondents aged ≥65 years than in respondents aged <65 years. An age ≥65 years, a disease history including hypertension with medication, arrhythmia, and depression, and using a chloride hot spring were independently and significantly associated with a drop in both systolic and diastolic blood pressure after night-time hot spring bathing.

In this prospective study, adults aged ≥65 years preferred to use paper questionnaires rather than mobile application questionnaires. Studies on electronic questionnaires using tablet computers reported no difficulty in most patients, except those who were older, those with less than a high school education, and those with comorbid medical conditions [19,20]. Similar to previous studies [20], we found that mobile questionnaires were favored by younger patients with a higher education level. Previous research shows that patients who use a mobile device daily appear to be more likely to prefer mobile questionnaires than those who do not [20]. It would be useful to extend this research to adults aged ≥65 years by examining how psychosocial factors such as self-efficacy, as well as physical factors such as visual or memory impairment, affect preferences for mobile and paper questionnaires. We believe that improving the ease of use and feasibility of mobile questionnaires for adults aged ≥65 years (e.g., by including video explanations of how to complete the questionnaire and appropriate consent acquisition procedures) might help to increase respondents’ satisfaction and preference for mobile questionnaires over paper questionnaires.

To date, only one study has investigated the association between habitual night-time hot spring bathing and a lower prevalence of hypertension [10]. However, several previous studies have demonstrated the benefits of traditional thermal therapy, including hot spring bathing, for hypertension [21–23]. The present study showed that night-time hot spring bathing resulted in a drop in both systolic and diastolic blood pressure. The reduction in both systolic and diastolic blood pressure after night-time bathing was significantly greater in respondents aged ≥65 years than in those aged <65 years. Tai et al. reported that Japanese hot water bathing, especially in the short time from the end of bathing to bedtime, was associated with lower night-time and sleep-time blood pressure and greater dipping in an older adult population [24]. Therefore, night-time hot spring bathing to reduce blood pressure may be more suitable for older adults than for younger adults.

The present study showed that hypertension with medication or arrhythmia was independently and significantly associated with a drop in both systolic and diastolic blood pressure after night-time hot spring bathing. This finding indicates the need for specific intervention strategies aimed at older adults living with hypertension or arrhythmia, one of which could be night-time hot spring bathing. Systolic blood pressure is considered the major predictor of coronary disease in older patients [25]. An elevation in systolic blood pressure is primarily due to diminished arterial compliance, and isolated systolic hypertension may result from an increase in cardiac output owing to anemia, aortic insufficiency, and arteriovenous fistula [26]. However, Protogerou et al. have suggested that lower diastolic blood pressure is associated with an increased risk of coronary heart disease in older adults [27]. The rapid drops in blood pressure after hot spring bathing may be detrimental for some patients. There is also evidence that low prestroke blood pressure is associated with mortality after stroke, particularly among patients with at least one comorbidity, such as smoking, heart disease, cancer, or dementia [28]. Understanding the effect of hot spring bathing on reducing the risk of coronary heart disease is important and requires further research; clarification of this association may be particularly relevant for assessing the reduced riskT of coronary heart disease in older patients after hot spring bathing. In this study, we did not follow the baseline blood pressure because of the difficulty of data collection. To evaluate whether the antihypertensive effects of hot spring bathing are persistent, we are currently conducting a prospective, longitudinal study in hospitalized patients with hypertension.

In the multivariate regression analysis, we found that depression was independently and significantly associated with a drop in both systolic and diastolic blood pressure after night-time hot spring bathing. We found that night-time hot spring bathing, which can improve sleep disorders owing to depression, may be associated with a drop in both systolic and diastolic blood pressure in older patients. In a large-scale study of an older population, taking a night-time hot spring bath shortened sleep onset latency if bathing was scheduled 1–3 hours before bedtime [27]. Brief exposure to sauna bathing can result in benefits for <1 hour, such as reduced blood pressure and improved arterial stiffness. However, sauna bathing for ≥3 weeks with repeated frequency can upregulate certain enzymes and pathways, which results in greater stress tolerance, an enhanced cellular environment, and improved health [23]. Owing to lack of physical activity and healthy nutrition in older patients with depression, practical interventions to prevent or improve hypertension, such as habitual night-time hot spring bathing, warrant additional attention.

Our study showed that hot spring bathing in a chloride spring bath was independently and significantly associated with a drop in both systolic and diastolic blood pressure after night-time hot spring bathing. Therefore, people with hypertension may benefit from taking a chloride spring bath. The effect of sodium chloride concentrations on physical and oxidative stability has been shown to be useful in cooking [28], and a clinical trial showed that sodium chloride was highly efficient in increasing core body temperature [29]. Additionally, a small Japanese study suggested that hot spring bathing in water containing sodium chloride maintained a higher rate of heat stability and was more efficient in elevating core body temperature than bathing in hot spring water without sodium chloride [29]. However, these findings should be confirmed in a prospective study with a control group, which is outside of the scope of the present study.

There were some study limitations. First, some selection bias was expected in this prospective study, which was performed at 14 institutions. In this study, bias was present owing to the following differences in data selection and other factors: a lack of data on respondents who engaged in hot spring bathing for the treatment of various diseases; respondents’ income, which might be correlated with some vascular diseases or the frequency of hot spring bathing; respondents’ lifestyle and diet, such as food consumption and obesity, sodium intake, drinking and smoking habits, consumption of coffee and tea, physical activity, and sleep; and the time at which respondents engaged in hot spring bathing. To minimize bias, we limited the inclusion criteria to patients with data on gender, age, disease history, and use of night-time hot spring bathing. Second, no long-term data on blood pressure were available. Therefore, further studies are required to assess the details of the long-term outcomes of patients who undergo hot spring bathing. Third, additional studies are needed that examine the effect of hot spring bathing while controlling for concurrent lifestyle and medication changes. Forth, some patients with primary or secondary hypertension may have been overlooked or the changes in blood pressure underestimated because of antihypertensive drug therapy. Additionally, there were no data specific to hot spring bathing, such as the duration of immersion, frequency, temperature, time, and years of habitual hot spring bathing. Finally, there is a lack of generalizability of the findings of this study to other populations.

 Conclusions

Although the use of mobile questionnaires in numerous medical fields has increased, we found that 99.3% of respondents aged ≥65 years chose to use paper questionnaires. Mobile questionnaires have the potential to increase clinical efficiency, improve physician—patient communication, and improve the patient’s encounter overall. Therefore, the ease and feasibility of mobile questionnaires may help to increase respondents’ preference for these questionnaires. This study showed a significantly lower drop in both systolic and diastolic blood pressure after using hot springs in respondents aged ≥65 years than in respondents aged <65 years. Night-time hot spring bathing was significantly associated with reduced blood pressure in older adults. Extending this research by examining how psychosocial factors may affect preferences for mobile and paper questionnaires could be beneficial, and further investigation is warranted.

 Supporting information File shows survey raw in <xref ref-type="supplementary-material" rid="pone.0299023.s002">S1 Table</xref> data.

Age, Q2; Age65over, over 65 years old; Disease, Q3 disease history; Hot spring chro, Q4 hot spring type; Time in and Time19, Q5 start time; PreSBP in, Q6 systolic blood pressure before hot spring bathing; PreDBP in, Q6 diastolic blood pressure before hot spring bathing; PostSBP out, Q6 systolic blood pressure after hot spring bathing; PostDBP out, Q6 diastolic blood pressure after hot spring bathing; SBP delta, drop in systolic blood pressure; DBP delta, drop in diastolic blood pressure; App, application.

(XLSX)

 English version of the Japanese questionnaire used in this study.

(DOCX)

We thank the respondents and clinical staff for their participation in the study. We appreciate the help of Mr. Yasuhiro Nagano (Mayor of Beppu), the Tourist Division of Beppu City, and the Beppu Tourist Hotel Association, especially Hotel Sunbury Annex, Hanabeppu, and Amane Resort, for enabling data collection. We thank Dr. Ellen Knapp, PhD, and Diane Williams, PhD, from Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript.

 References Whelton PK, Carey RM, Aronow WS, Casey DE Jr., Collins KJ, Dennison Himmelfarb C, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018; 71: e13–e115. doi: 10.1161/HYP.0000000000000065 29133356. Muntner P, Carey RM, Gidding S, Jones DW, Taler SJ, Wright JT Jr., et al. Potential US Population Impact of the 2017 ACC/AHA High Blood Pressure Guideline. Circulation. 2018; 137: 109–118. doi: 10.1161/CIRCULATIONAHA.117.032582 29133599. He FJ, Li J, Macgregor GA. Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials. British Medical Journal. 2013; 346: f1325. doi: 10.1136/bmj.f1325 23558162. Tuck ML, Sowers J, Dornfeld L, Kledzik G, Maxwell M. The effect of weight reduction on blood pressure, plasma renin activity, and plasma aldosterone levels in obese patients. New England Journal of Medicine. 1981; 304: 930–933. doi: 10.1056/NEJM198104163041602 7010165. Forman JP, Stampfer MJ, Curhan GC. Diet and lifestyle risk factors associated with incident hypertension in women. JAMA. 2009; 302: 401–411. doi: 10.1001/jama.2009.1060 19622819. Carnethon MR, Evans NS, Church TS, Lewis CE, Schreiner PJ, Jacobs DR Jr., et al. Joint associations of physical activity and aerobic fitness on the development of incident hypertension: coronary artery risk development in young adults. Hypertension. 2010; 56: 49–55. doi: 10.1161/HYPERTENSIONAHA.109.147603 20516395. Virdis A, Giannarelli C, Neves MF, Taddei S, Ghiadoni L. Cigarette smoking and hypertension. Curr Pharm Des. 2010; 16: 2518–2525. doi: 10.2174/138161210792062920 20550499. Teramoto M, Yamagishi K, Muraki I, Tamakoshi A, Iso H. Coffee and Green Tea Consumption and Cardiovascular Disease Mortality Among People With and Without Hypertension. J Am Heart Assoc 2023; 12: e026477. doi: 10.1161/JAHA.122.026477 36542728. Carnethon MR, Johnson DA. Sleep and Resistant Hypertension. Curr Hypertens Rep. 2019; 21: 34. doi: 10.1007/s11906-019-0941-z 30953264. Yamasaki S, Tokunou T, Maeda T, Horiuchi T. Hot spring bathing is associated with a lower prevalence of hypertension among Japanese older adults: a cross-sectional study in Beppu. Sci Rep. 2022; 12: 19462. doi: 10.1038/s41598-022-24062-3 36376349. https://www.env.go.jp/content/900492871.pdf#search, Japanese Ministry of Environment. ‘The ABCs for the Safe and Secure Use of Onsen’. Buis LR, Roberson DN, Kadri R, Rockey NG, Plegue MA, Danak SU, et al.Understanding the Feasibility, Acceptability, and Efficacy of a Clinical Pharmacist-led Mobile Approach (BPTrack) to Hypertension Management: Mixed Methods Pilot Study. J Med Internet Res. 2020; 22: e19882. doi: 10.2196/19882 32780026. Maeda T, Mimori K, Suzuki S, Horiuchi T, Makino N. Preventive and promotive effects of habitual hot spa-bathing on the elderly in Japan. Sci Rep. 2018; 8: 133. doi: 10.1038/s41598-017-18488-3 29317745. Fritz F, Balhorn S, Riek M, Breil B, Dugas M. Qualitative and quantitative evaluation of EHR-integrated mobile patient questionnaires regarding usability and cost-efficiency. Int J Med Inform. 2012; 81: 303–313. doi: 10.1016/j.ijmedinf.2011.12.008 22236957. Aiello EJ, Taplin S, Reid R., Hobbs M, Seger D, Kamel H, et al. In a randomized controlled trial, patients preferred electronic data collection of breast cancer risk-factor information in a mammography setting. J Clin Epidemiol. 2006; 59: 77–81. doi: 10.1016/j.jclinepi.2005.07.007 16360564. George P, Dumenco L, Doyle R, Dollase R. Incorporating iPads into a preclinical curriculum: a pilot study. Med Teach. 2013; 35: 226–230. doi: 10.3109/0142159X.2012.735384 23425119. Dorr M, Lesmes LA, Lu ZL, Bex PJ. Rapid and reliable assessment of the contrast sensitivity function on an iPad. Invest Ophthalmol Vis Sci. 2013; 54: 7266–7273. doi: 10.1167/iovs.13-11743 24114545. Kanda Y. Investigation of the freely available easy-to-use software ’EZR’ for medical statistics. Bone Marrow Transplantation. 2013; 48: 452–458. doi: 10.1038/bmt.2012.244 23208313. Velikova G, Wright EP, Smith AB, Cull A, Gould A, Forman D, et al. Automated collection of quality-of-life data: a comparison of paper and computer touch-screen questionnaires. J Clin Oncol. 1999; 17: 998–1007. doi: 10.1200/JCO.1999.17.3.998 10071295. Hess R, Santucci A, McTigue K, Fischer G, Kapoor W. Patient difficulty using tablet computers to screen in primary care. J Gen Intern Med. 2008; 23, 476–480. doi: 10.1007/s11606-007-0500-1 18373148. Kataoka T, Aoyama Y, Sakoda A, Nakagawa S, Yamaoka K. Basic study on biochemical mechanism of thoron and thermal therapy. Physiological Chemistry and Physics and Medical NMR. 2006; 38: 85–92. 18472469. Chen Z, Yang J, Zhu L, Zhang A, Wang Z, Liu P, et al. Classification of typical hot springs and their relationship with health in Guizhou, China. Evironmental Geochemistry and Health. 2021; 43: 1287–1304. doi: 10.1007/s10653-020-00724-x 32974884. Henderson KN, Killen LG, O’Neal EK, Waldman HS. The Cardiometabolic Health Benefits of Sauna Exposure in Individuals with High-Stress Occupations. A Mechanistic Review. International Journal of Environmental Research and Public Health. 2021; 18: 1105. doi: 10.3390/ijerph18031105 33513711. Tai Y, Saeki K, Yamagami Y, Yoshimoto K, Kurumatani N, Nishio K, et al. Association between timing of hot water bathing before bedtime and night-/sleep-time blood pressure and dipping in the elderly: a longitudinal analysis for repeated measurements in home settings. Chronobiology International. 2019; 36: 1714–1722. doi: 10.1080/07420528.2019.1675685 31610699. Franklin SS, Larson MG, Khan SA, Wong ND, Leip EP, Kannel WB, et al. Does the relation of blood pressure to coronary heart disease risk change with aging? The Framingham Heart Study. Circulation. 2001; 103: 1245–1249. doi: 10.1161/01.cir.103.9.1245 11238268. Chobanian AV. Clinical practice. Isolated systolic hypertension in the elderly. New England Journal of Medicine. 2007; 357: 789–796. doi: 10.1056/NEJMcp071137 17715411. Tai Y, Obayashi K, Yamagami Y, Yoshimoto K, Kurumatani N, Nishio K, et al. Hot-water bathing before bedtime and shorter sleep onset latency are accompanied by a higher distal-proximal skin temperature gradient in older adults. Journal of Clinical Sleep Medicine. 2021; 17: 1257–1266. doi: 10.5664/jcsm.9180 33645499. Min B, Cordray JC, Ahn DU. Effect of NaCl, myoglobin, Fe(II), and Fe(III) on lipid oxidation of raw and cooked chicken breast and beef loin. J Agric Food Chem. 2010; 58: 600–605. doi: 10.1021/jf9029404 19904983. Maeda T, Kudo Y, Horiuchi T, Makino N. Clinical and anti-aging effect of mud-bathing therapy for patients with fibromyalgia. Mol Cell Biochem. 2018; 444: 87–92. doi: 10.1007/s11010-017-3233-4 29214470. 10.1371/journal.pone.0299023.r001 Decision Letter 0 Samala Venkata Vikramaditya Academic Editor 2024 Vikramaditya Samala Venkata This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Submission Version 0

9 Jan 2024

PONE-D-23-34165Night-time hot spring bathing is associated with improved blood pressure control: A mobile application and paper questionnaire studyPLOS ONE

Dear Dr. YAMASAKI,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please refer to the reviewer questions and revision recommendations. 

Please submit your revised manuscript by Feb 23 2024 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Vikramaditya Samala Venkata

Academic Editor

PLOS ONE

Journal Requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at 

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and 

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. We noticed you have some minor occurrence of overlapping text with the following previous publication(s), which needs to be addressed:

https://www.auajournals.org/doi/10.1016/j.juro.2018.03.117

In your revision ensure you cite all your sources (including your own works), and quote or rephrase any duplicated text outside the methods section. Further consideration is dependent on these concerns being addressed.

3. Thank you for stating the following in your Competing Interests section:  

"NO authors have competing interests"

Please complete your Competing Interests on the online submission form to state any Competing Interests. If you have no competing interests, please state "The authors have declared that no competing interests exist.", as detailed online in our guide for authors at http://journals.plos.org/plosone/s/submit-now 

 This information should be included in your cover letter; we will change the online submission form on your behalf.

4. In the online submission form, you indicated that [Insert text from online submission form here]. 

All PLOS journals now require all data underlying the findings described in their manuscript to be freely available to other researchers, either 1. In a public repository, 2. Within the manuscript itself, or 3. Uploaded as supplementary information.

This policy applies to all data except where public deposition would breach compliance with the protocol approved by your research ethics board. If your data cannot be made publicly available for ethical or legal reasons (e.g., public availability would compromise patient privacy), please explain your reasons on resubmission and your exemption request will be escalated for approval. 

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

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.

Reviewer #1: Yes

Reviewer #2: Partly

Reviewer #3: Partly

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: I Don't Know

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy 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.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

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.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

5. Review Comments to the Author

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)

Reviewer #1: This is a very good and interesting study that shows effects of hot spring bathing in different salt and how it can lower Blood pressure . The statistical analysis was drawn in multiple individuals male and female with and without additional comorbidities- overall I enjoyed reading the study it does engage the audience and there are some minor revisions as suggested in the PDF attached

Reviewer #2: - Its not clear ,if the hypertension was primary or secondary hypertension

- Appx 50% of the population in the study were using medications for control of Blood pressure

- Timing of the repeat blood pressure check after the hot spring bath was not clear . Was repeat blood pressure checked immediately following the bath or the next day

- Effect of decreased blood pressure was it transient ? persistent in patients who were not using Anti Hypertensive medications ?

- Were there any complications /side effects or adverse events during the study

Reviewer #3: Interesting study question and innovative study design with both mobile and paper questionnaires. I have a few thoughts

1. There is some discrepancy between the table and the discussion regarding the numbers. Especially the median blood pressure drop post-spring bathing.

2. May be worth mentioning how the BP was recorded pre and post-spring bath. This is important, as lack of uniformity would affect the study results directly.

3. The claimed magnitude of BP drop, especially in the> 65-year age group, is significant and has not been shown with any other intervention in the past. But, as mentioned this data may not be generalized. Lack of data regarding concurrent lifestyle and medication changes limits the validity of this finding.

4. Spelling check especially in the tables.

5. I commend the authors for the additional information on mobile vs paper questionnaire. This definitely gives prespective for future research involving different age groups.

6. Please explain the inverse relationship of some risk factors with blood pressure drop in detail.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Dr Gurpreet Kaur Saini

Reviewer #2: No

Reviewer #3: Yes: ramprakash devadoss

**********

[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.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. 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 figures@plos.org. Please note that Supporting Information files do not need this step.

Submitted filename: PLOS one case on hot spring and HTN .pdf

 10.1371/journal.pone.0299023.r002 Author response to Decision Letter 0 Submission Version 1

22 Jan 2024

Dr. Vikramaditya Samala Venkata

Academic Editor

PLOS ONE

15 January 2024

Re: Manuscript no. PONE-D-23-34165

Dear Dr Venkata,

We would like to thank you and the reviewers for the constructive comments on our manuscript entitled, “Night-time hot spring bathing is associated with improved blood pressure control: A mobile application and paper questionnaire study.” We have revised the manuscript in accordance with these comments; revisions to the text are shown in yellow highlight. Our point-by-point responses to the comments are provided below.

We hope that our manuscript will now be considered suitable for publication in PLOS ONE. We look forward to hearing from you at your earliest convenience.

Yours sincerely,

Satoshi Yamasaki, MD, PhD

Department of Internal Medicine

Kyushu University Beppu Hospital

4546 Tsurumihara, Tsurumi, Beppu, Oita 874-0838, Japan

Tel: +81-977-27-1600; Fax: +81-977-27-1641

E-mail: yamas009@gmail.com

Review Comments to the Author

Reviewer #1: This is a very good and interesting study that shows effects of hot spring bathing in different salt and how it can lower Blood pressure . The statistical analysis was drawn in multiple individuals male and female with and without additional comorbidities- overall I enjoyed reading the study it does engage the audience and there are some minor revisions as suggested in the PDF attached

RESPONSE: Thank you for your thoughtful and constructive comments on our manuscript; we appreciate your help. In accordance with your suggestions, we have revised the relevant text in the manuscript (page 2, line 18; page 3, line 45; page 5, lines 76–77; page 17, lines 252–253 and line 257).

Reviewer #2: - Its not clear ,if the hypertension was primary or secondary hypertension

RESPONSE: Thank you for raising this issue. We acknowledge that more details about the type of hypertension are needed. We have added a mention of these factors to the Limitations (page 19, line 287).

- Appx 50% of the population in the study were using medications for control of Blood pressure

RESPONSE: Thank you for your constructive comments on our manuscript. As you mention, 51.2% in the mobile group and 81.3% in the paper group of the study population were using hypertension medications. This may be owing to our promotion of the preventive effect of high blood pressure by engaging in night-time hot spring bathing (Reference No. 10). We acknowledge that participants’ use of antihypertensive medication may have made it difficult to clarify the effect of hot spring bathing on blood pressure. We have mentioned this factor as a study limitation (page 19, lines 285–286).

- Timing of the repeat blood pressure check after the hot spring bath was not clear . Was repeat blood pressure checked immediately following the bath or the next day

RESPONSE: To address your question, we have added some text explaining this point to the Material and Methods (page 6, lines 97–98).

- Effect of decreased blood pressure was it transient ? persistent in patients who were not using Anti Hypertensive medications ?

RESPONSE: Thank you for raising this issue. We did not have data on the long-term effects of hot spring bathing. We acknowledge the need for long-term information about changes in blood pressure, and have mentioned this factor as a study limitation (page 19, lines 283–285).

- Were there any complications /side effects or adverse events during the study

RESPONSE: Thank you for raising this issue. We acknowledge the need for more detail about the complications, side effects, and adverse events during the study. We have added a mention of these factors to the Results (page 10, lines 165–166).

Reviewer #3: Interesting study question and innovative study design with both mobile and paper questionnaires. I have a few thoughts

1. There is some discrepancy between the table and the discussion regarding the numbers. Especially the median blood pressure drop post-spring bathing.

RESPONSE: We apologize for the unclear text. We have revised the Abstract, Results, and Discussion to clarify these data (page 2, line 31; page 3, line 35; page 10, line 163; page 13, lines 192; page 14, line 196; page 15, lines 217, 218 and 226; page 17, lines 248, 250 and 262; page 20, line 301). We hope that this has clarified the data interpretation. However, we welcome your comments on any specific aspects of the data presentation you feel are still unclear.

2. May be worth mentioning how the BP was recorded pre and post-spring bath. This is important, as lack of uniformity would affect the study results directly.

RESPONSE: In accordance with your suggestion, we have added an explanation of this to the Material and Methods (page 6, lines 97–98).

3. The claimed magnitude of BP drop, especially in the> 65-year age group, is significant and has not been shown with any other intervention in the past. But, as mentioned this data may not be generalized. Lack of data regarding concurrent lifestyle and medication changes limits the validity of this finding.

RESPONSE: Thank you for your helpful comments. We acknowledge that this study has several limitations, including the effect of various unmeasured factors that correlate with blood pressure, such as lifestyle and diet (food consumption and obesity), sodium intake, drinking and smoking habits, consumption of coffee and tea, physical activity, and sleep. We have mentioned these as study limitations in the Discussion (page 18, lines 278–280; page 19, lines 285–286).

4. Spelling check especially in the tables.

RESPONSE: We apologize for any errors. We have revised the tables to ensure that the spelling is correct (pages 9–10, line 155; pages 13–14, lines 180–181).

5. I commend the authors for the additional information on mobile vs paper questionnaire. This definitely gives perspective for future research involving different age groups.

RESPONSE: Thank you for your comment. In the Discussion, we have briefly expanded on the potential of mobile questionnaires for adults aged ≥65 years (pages 14–15, lines 209–211).

6. Please explain the inverse relationship of some risk factors with blood pressure drop in detail.

RESPONSE: To address your query, we have added some text explaining this point to the Discussion (page 16, lines 233–239).

Submitted filename: Response to Reviewers_20240115.docx

 10.1371/journal.pone.0299023.r003 Decision Letter 1 Samala Venkata Vikramaditya Academic Editor 2024 Vikramaditya Samala Venkata This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Submission Version 1

5 Feb 2024

Night-time hot spring bathing is associated with improved blood pressure control: A mobile application and paper questionnaire study

PONE-D-23-34165R1

Dear Dr. YAMASAKI,

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. 

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.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, 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 authorbilling@plos.org.

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 onepress@plos.org.

Kind regards,

Vikramaditya Samala Venkata

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

 10.1371/journal.pone.0299023.r004 Acceptance letter Samala Venkata Vikramaditya Academic Editor 2024 Vikramaditya Samala Venkata This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

27 Mar 2024

PONE-D-23-34165R1

PLOS ONE

Dear Dr. YAMASAKI,

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.

At this stage, our production department will prepare your paper for publication. This includes ensuring the following:

* All references, tables, and figures are properly cited

* All relevant supporting information is included in the manuscript submission,

* There are no issues that prevent the paper from being properly typeset

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.

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 onepress@plos.org.

If we can help with anything else, please email us at customercare@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Vikramaditya Samala Venkata

Academic Editor

PLOS ONE