A Markov transition analysis to study changes in HIV prevention strategies among men who have sex with men in the French ANRS-PREVENIR cohort

Despite various biomedical and behavioral prevention strategies, new HIV seroconversions are disproportionately higher among gay and bisexual men who have sex with men (GBMSM). Using data from the French PrEP cohort ANRS-PREVENIR, this study aimed to investigate prevention strategies among this population and to analyze factors that may shape GBMSMs’ sexual behaviors. We defined three protection states as follows: self-dependent protection (SDP), which covered condom and/or PrEP use, partner-dependent protection (PDP), whereby the partner self-declared being either seronegative or seropositive with an undetectable viral load, and no protection (NP). We constructed a composite variable reflecting the degree of concordance between actual and perceived risk. A continuous-time multi-state Markov model was used to determine transition probabilities between protection states over time. Hazard ratios and their 95% confidence intervals (HR(95%CI)) were computed to identify factors associated with transitions. Irrespective of the protection state at baseline (i.e., SDP, PDP, NP), the highest Markov transition probabilities were to transition from one state to the same state at the next follow-up visit over the entire study period; specifically, the probability [95%CI] was 0.920 [0.916,0.924] for SDP, 0.783 [0.769,0.797] for PDP, and 0.584 [0.546,0.615] for NP. Event-driven PrEP (3.34(2.89–3.85)) and PrEP naivety (1.19(1.04–1.36)) were associated with an increased probability of transitioning from SDP to PDP. PrEP naivety (1.44(1.23–1.69)) and event-driven PrEP (4.15(3.47–4.96)) were also associated with an increased probability of transitioning from SDP to NP. A higher actual/perceived risk concordance score, i.e., higher actual risk and either a greater level of discordance or not considering risk, was associated with a reduced probability to transition from SDP to PDP (0.96 (0.92–0.99)), and was not associated with the transition from SDP to NP. Most GBMSM in our study transitioned from one state of protection to the same state at the next follow-up visit over the entire study period, highlighting the need for close counselling when GBMSM adopt a protection strategy for the first time, as it will shape their future strategies. Our findings also suggest that PrEP-naive and event-driven PrEP users have an increased probability of transitioning to protection strategies that are not self-controlled, raising questions about their vulnerability to HIV acquisition.