Social and behavioural factors associated with risky sexual behaviours among university students in nine ASEAN countries: a multi-country cross-sectional study.

While university students are potential human resources, this population group is particularly involved in health risk behaviours. Preventing risky sexual behaviours among them would contribute to prevention of HIV, sexually transmitted infections (STIs), and unwanted pregnancies, which have posed a great burden on population health. This study was therefore conducted to identify social and behavioural factors associated with risky sexual behaviours among university students in nine ASEAN countries. A multi-country, cross-sectional study was conducted in 2015 among university students by a network of researchers in the selected countries. A convenient sampling method and stratified random sampling procedures were employed to select universities and students, respectively. A structured questionnaire was translated into national languages of the participating countries and used to collect data from the selected students in the classrooms. Using STATA, Chi-square test was used to test differences in proportions, and multinomial logistic regression analyses were performed to obtain relative risk ratios and 95% confidence intervals. Multivariate logistic regression analysis was performed with to identify independent social and behavioural factors associated with non-condom use at last sexual intercourse. In total, 8,836 students with a mean age of 20.6 (SD = 2.0) participated in the study. Most of them (98.5%) were unmarried. In all countries, male students were significantly more likely to have two or more sexual partners in the past 12 months compared to female students (4.8% vs. 1.1%, p < 0.001). Female students were significantly more likely to report unprotected sex compared to male students (50.5% vs. 58.8%, p = 0.01). Results of multivariable logistic regression analyses showed that students who reported having two or more partners in the past 12 months were significantly more likely to be male, be aged between 20-30, be current tobacco smokers, be binge drinkers, have severe depressive symptoms, and have been in a physical fight in the past 12 months, compared to students who reported having less than two sexual partners in the past 12 months. Health intervention programmes to prevent and control STIs, especially HIV infection, should focus on university students having the social and behavioural characteristics that are associated with risky sexual behaviours.