Abstract
BACKGROUND: Men who have sex with men (MSM) are key populations for HIV infection. Post-exposure prophylaxis (PEP) has been confirmed to be an effective measure for preventing HIV transmission. This study aimed to investigate the usage of PEP among MSM in Qingdao and its associated factors, analyze the impact of PEP usage on risk behaviors, and offer insights for HIV prevention. METHODS: Between April and August 2021, a cross-sectional survey was conducted in Qingdao, relying on local community-based organizations (CBOs) and employing a snowball sampling method to recruit eligible MSM. We gathered sociodemographic information, behavioral data, and PEP usage details from the participants. The analysis of factors associated with PEP utilization among MSM was performed using a logistic regression model. Subsequently, a follow-up visit was conducted six months later, collecting behavioral information from the participants. Generalized estimating equations fitting Poisson regression were utilized to analyze behavioral changes during the follow-up for PEP users and non-PEP users. RESULTS: A total of 602 MSM were enrolled in this study, with a median age of 30.0 years. Among them, 140 individuals used PEP in the last 6 months, resulting in a usage rate of 23.3% (140/602). Factors associated with PEP usage included monthly income ≥ 5000 RMB (aOR = 2.092, 95%CI: 1.366-3.203) and engaging in group sex ≥ 3 times in the last 6 months (aOR = 1.844, 95%CI: 1.067-3.189). In the follow-up survey, 467 individuals participated, comprising 112 PEP users and 355 non-PEP users. Compared to the baseline, the proportion of non-PEP users with Rush Popper usage frequency ≥ 1 time/week increased from 19.3% to 34.4% during follow-up (RR = 1.671, 95%CI: 1.302-2.146), and the proportion of those engaging in unprotected anal intercourse in the past 6 months increased from 95.5% to 98.6% (RR = 1.029, 95%CI: 1.004-1.056). However, the risk behaviors of PEP users exhibited no significant changes during the study period (P > 0.05). CONCLUSIONS: Higher frequency of group sex and higher monthly income emerged as facilitating factors for PEP usage among MSM in Qingdao. Beyond its efficacy in preventing HIV infection, PEP may also play a role in managing the occurrence of risk behaviors among MSM. Consequently, there is a pressing need to intensify efforts to promote PEP uptake among MSM as a strategy to control the spread of HIV.