Impact of Peer Referral on Pre-Exposure Prophylaxis Adherence and Persistence Among Men Who Have Sex with Men: A Cohort Study in China.

Peer referral leverages social networks to connect individuals with health services, potentially enhancing pre-exposure prophylaxis (PrEP) use. This study aims to investigate the impact of peer referral on PrEP adherence and persistence among men who have sex with men (MSM) in China. This study is nested in a 12-month PrEP (FTC/TDF) demonstration trial in China from September 2021 to December 2023. Peer referral was defined as participants being referred by peers already enrolled in the trial. PrEP adherence was measured as taking four or more pills per week for daily users or following the 2 + 1 + 1 event-driven regimen at least 75% of the time. PrEP persistence was defined as the time from initiation to discontinuation. We collected data from the first 6 months of follow-up and used generalized estimating equations and Cox regression models to evaluate the association between peer referral and PrEP adherence and persistence. A total of 1,131 MSM initiated PrEP, with 121 (10.7%) referred by peers. At month 6, adherence rates were 75.0% for peer-referred MSM and 67.1% for non-peer-referred MSM. Peer-referred MSM had higher adherence than non-peer-referred MSM (aRR = 1.11, 95% CI: 1.01-1.22). Regarding persistence, 812 (71.8%) MSM continued using PrEP at 6 months of follow-up, and peer-referred MSM were more likely to persist with PrEP (aHR = 1.85, 95% CI: 1.17-2.91). These findings demonstrate the potential of peer referral in promoting PrEP use among MSM, suggesting the value of powerful peer-based interventions like peer navigation in future PrEP outreach.