Exploring the relationship between HIV Testing frequency and sexual behavior, prevention prophylaxis use among MSM in Southern China

Aim This study aimed to explore the association between HIV testing trajectories, sexual behavior characteristics and HIV exposure prevention prophylaxis use, to provide a basis for developing more precise HIV prevention strategies. Study design This analysis utilized pseudonymized data from a three-arm, open-label randomized controlled trial (RCT) conducted in Guangxi, China, between 2021 and 2023. Methods This prospective cohort study enrolled 327 participants from southern China. Longitudinal data—including HIV testing, sexual risk behaviors, and prophylaxis use (PrEP/PEP)—were collected at baseline and quarterly for one year. Group-based trajectory modeling (GBTM) was used to identify behavioral patterns, and person-years (PY) of follow-up were calculated to estimate incidence densities of PrEP/PEP use and STI occurrence. Results A total of 76.45% of men who have sex with men (MSM) received HIV testing less frequently than once every three months, and HIV self-testing (HIVST) was not significantly associated with increased rates of HIV testing (HT). In the HT model, MSM who underwent middle-frequency HT were less likely to report having fewer temporary sexual partners (OR 0.120, 95% CI 0.017–0.85, P = 0.034) and regular sexual partners (OR 0.502, 95% CI 0.267–0.943, P = 0.032). The use of PrEP increased with higher HT frequency, demonstrating a 3.39-fold (95% CI: 1.377–8.843, P = 0.008) increase in the middle frequency group and a 7.335-fold (95% CI: 2.505–21.475, P < 0.001) increase in the high frequency group compared to the low frequency group. PEP use also increased with higher HT frequency, showing a 6.129-fold (95% CI: 1.921–19.553, P = 0.002) increase in the high frequency group compared to the low frequency group. Conclusions While frequent HIV testing demonstrates significant associations with increased sexual partner numbers, its role in facilitating consistent use of HIV exposure prevention prophylaxis remains clinically valuable.