Factors associated with high risky sexual behavior among students engaging in casual heterosexual activity: a cross-sectional study in Zhejiang Province, Eastern China.

Objective: This study aimed to investigate the factors associated with engagement in high risky sexual behavior among college students who have engaged in casual heterosexual behaviors. Method: A cross-sectional study was performed in Zhejiang Province, Eastern China between November and December 2020. Stratified cluster sampling method was used for the survey, and demographic and behavioral data was collected through questionnaires for statistical analysis. Results: In total, 2,581 university students self-reported engaging in heterosexual behavior in the previous year, accounting for 6.15% (2,581/41,940) of the student population. From this group, 425 college students who reported engaging in casual heterosexual behaviors in the past year were included, of whom 53 (12.47%, 53/425) engaged in high risky sexual behavior. The results of the multivariable logistic regression analysis indicated that the participants who accepted sexual behavior with men who had sex with men (MSM), those who involved in commercial sexual activities with monetary transactions in the past year were more likely to have engaged in high risky sexual behavior. Additionally, the participants who consistently used condoms during sexual activity with casual sexual partners and those who used condoms occasionally were less likely to have engaged in high risky sexual behavior. Conclusion: This study identified several key factors associated with high risky sexual behavior among college students engaging in casual heterosexual experience. It is advisable to incorporate sexual risk awareness and sex moral education into health programs for this population. We also need enhance students' understanding of HIV transmission risks and promote consistent condom use, in order to reduce the likelihood of HIV infection.