A cross-sectional design was conducted online, and a questionnaire was disseminated via the participants’ WhatsApp groups from February 29 to April 3, 2024.

The study was carried out among university students in universities in southwestern Nigeria.

Inclusion criteria were based on consent to participate in the study, and those who did not consent were excluded.

The total population of students from selected universities were 51000 (Afe Babalola University: 8500; Obafemi Awolowo University: 26000; University of Ibadan: 16500) for 2022/2023 session. A default proportion of 50% (0.5) was adopted for the sample size calculation as per the standard protocol for studies with no previous data. The sample size was calculated to be 382 participants using Raosoft®, an online calculator with a 95% confidence interval and 5% margin of error.

Convenience sampling was used to select three universities in southwestern Nigeria based on popularity and population in Nigeria. The universities included Afe Babalola University, Obafemi Awolowo University, and the University of Ibadan. Proportionate allocation was employed to determine the desired number of participants from university (Table 1).

Questionnaires were distributed to departments of the institutions through WhatsApp groups of students, with reminders sent as needed.

Data were collected using a 26-item semi-structured online questionnaire developed following a comprehensive literature review [13–16]. The questionnaire was designed with three main sections:

This section gathered essential demographic information, including age, gender, institution, college/faculty, department, level, ethnicity, and marital status.

Participants were asked to specify the brand of antimalarial drugs they used, the number of pills/tablets in a pack, and the dosage form.

This section was made up of 13 knowledge questions that evaluated participants’ previous usage experience, frequency and timing of doses, method of consumption, reactions to the medication, actions taken upon adverse effects, and storage practices. The questions consisted of multiple-choice as well as yes/no formats. Of the 13 questions, 8 were scored knowledge-based items, while the remaining 5 assessed prior use and experiential practices. The maximum possible knowledge score was 8, with each correct answer awarded 1 point and incorrect answers given a score of 0. Based on their scores, students’ knowledge was categorised into three levels: good (≥70%), fair (50–69%), and poor (<50%). The questionnaire is attached as a supplementary file (S1 Appendix).

Content and face validity were carefully evaluated to ensure the instrument’s accuracy and comprehensiveness. Internal consistency was assessed through a pre-test involving 10 undergraduate students of Afe Babalola University, Ado-Ekiti, Nigeria, with reliability measured using Cronbach’s Alpha coefficient. The data from these students were excluded from the final analysis. An overall coefficient value of 0.75 was obtained.

The questionnaire was prepared using Google Forms and distributed electronically to student department groups across various universities. The departments were categorised into three groups; Healthcare for departments that offer healthcare based courses such as medicine, pharmacy, public health etc.; Science-based for departments offering science and technology-based courses such as Engineering, Biology, Mathematics, physics, and chemistry, while Arts-based courses comprised of other courses that did not meet the criteria for healthcare and art-based courses such as; law, social/management sciences, and English etc. The recruitment of participants was conducted through direct researcher involvement and university collaboration, where researchers and collaborators disseminated the questionnaires in relevant student WhatsApp groups after obtaining permission and consent. Also, the researchers liaised with student representatives in the various departments, who served as intermediaries to help disseminate the questionnaires. This approach ensured a more comprehensive and representative sample, enhancing validity and reliability.

Ethical approval for this study was obtained from the Afe Babalola Multisystem Hospital Health Research Ethics Committee (ABUADHREC) prior to data collection (Approval No.: AMSH/RET/24/001) (S1 File). The ethical approval granted by ABUADHREC was formally accepted by the University of Ibadan and Obafemi Awolowo University; therefore, separate ethical approvals were not required from each participating institution. An online written consent was obtained before study commencement and participant confidentiality and anonymity were strictly maintained throughout and after the study. The study was conducted in accordance with the ethical principles of the Declaration of Helsinki.

The sociodemographic characteristics obtained were summarised using descriptive statistics, including frequencies and percentages. The differences in knowledge across categorical variables including gender, age, level of study, course of study, previous use of the antimalarial drug, and the time since last use of the antimalarial drug were analysed using the independent sample t-test and one-way analysis of variance (ANOVA). All statistical tests were two-sided, with a significance level set at p < 0.05. Statistical analyses were conducted using Statistical Product and Service Solutions (SPSS), version 27.

In this study, 392 students from three universities agreed to participate. Among them, 163 (41.60%) were male, and the mean age was 19.53 ± 2.09 years with minimum age of 16 years and maximum age of 27 years. About 17% study arts-based courses while a larger proportion studied science-based courses (138, 35.20%) and healthcare-based courses (188, 48%). The antimalarial medication taking profile of the participants was assessed, and it was reported that only 95.20% had previously taken the antimalarial drug before. One hundred and six students (28.40%) stated that they last took the antimalarial medication ago while 81 (21.70%) took the drug 4–6 months ago. The students also reported that they had taken the drug 1–2 times (177, 47.50%) and 3 times or more (88, 23.60%) during the year. This has been summarized in Table 2. The students also identified Amatem^® (147 (39.41%)), Arthemed^® (82 (21.98%)) and Coartem^® (72 (19.30%)) were the commonest brands of antimalarial medications taken before while Lonart^® (66 (17.69%)), Arenax^® (4 (1.07%)) and Lumapil^® (2 (0.54%)) were least taken by the participants.

Table 3 summarises the students’ knowledge of usage of artemether-lumefantrine in this study. When asked the best time to start taking the antimalarial medicine the responses obtained included after 2 hours (68/392, 17.30%), after food (8/392, 2%), immediately (227/392, 57.90%).

Also, majority of the students (253/392, 64.50%) stated that the second dose of the medication should be taken 8 hours after the first dose while 9/392 (2.30%) reported that it should be taken immediately after the first dose. Thirty-one students (7.90%) reported that it would take then 4 days to complete the medication while 13/392 (3.30%) stated that it takes 2 days. More than 6.50% (26/392) reported that they would never complete the dose and that they would stop immediately after feeling better. When asked about how best they should take their medication, 372/392 (94.90%) stated that they would swallow with water after food and 7/392 (1.8%) reported that they would swallow with drinks and milk. The students identified vomiting/diarrhoea (50/392 (12.80%)), sleep disturbances (12/392 (3.10%)), body weakness (4/392 (1.00%)) as the possible side effects associated with the medication. They also reported that they would get adequate rest/sleep (7/392 (1.80%)), report to prescriber (37/392 (9.40%)), stop taking medicine (100/392 (25.50%)) and taking the next dose (185/392 (47.20%)) as steps they would take when faced with side effects of the medication.

One hundred students (25.50%) reported that they would stop taking the medication if they are to vomit immediately after taking the antimalarial drug while 47.20% (185/392) reported that they would take two doses during time for the next dose. A total of three hundred and two students (77%) did not know the proper way of storing the antimalarial medication. About 65% (254/392) stated that they would store the drug in the cupboard while 90/392 (23%) opted to storing the medicine in an open space. Overall, 175/392 students (44.60%) of the students showed poor knowledge of usage of the antimalarial drugs prescribed to them.

Table 4 shows statistical differences in knowledge scores based on demographics, and antimalarial medication taking profile of students. There was a statistically significant difference in knowledge scores based on student levels (p = 0.001) and previous usage of antimalarial drug (p = 0.04) by the students. Also, female students (p = 0.07), students of higher age (p = 0.27) and healthcare students (p = 0.28) had better knowledge than male students, students of lower age and students in other disciplines respectively but this was not statistically significant.

This study, while providing valuable insights into the knowledge and practices related to antimalarial medication use among university students, has several limitations. Firstly, the use of an online questionnaire distributed via WhatsApp groups may have introduced sampling bias, potentially excluding students without access to smartphones or the internet. This limitation could impact the generalizability of the findings to the broader student population. Also, the reliance on self-reported data poses another limitation. Participants’ responses may be influenced by recall bias or inaccuracies in their understanding of their own medication practices and knowledge.

The cross-sectional design of the study provides only a snapshot of students’ knowledge and behaviours at a single point in time. This design does not account for how knowledge and practices might evolve over time. Longitudinal studies could offer deeper insights into these changes and their impacts on antimalarial medication use.

Furthermore, the questionnaire may not have captured the full depth of participants’ knowledge about antimalarial medications. A more comprehensive assessment, including qualitative methods such as interviews or focus groups, could yield more detailed information on participants’ understanding and practices. The study’s findings are also limited in their generalizability. Conducted among university students in southwestern Nigeria, the results may not be applicable to other regions or populations.

Additionally, while the study considered prior antimalarial usage, it did not account for variations in the type or duration of previous treatments. Such factors could influence current knowledge and practices, suggesting a need for more detailed data on this aspect. The study did not assess laboratory-confirmed malaria diagnosis, Plasmodium species, or prescriber source, as the focus was on knowledge and reported use patterns. As with all self-administered online surveys, the possibility of participants consulting external sources while completing the questionnaire cannot be entirely excluded.