Peer Influence on Motivation to Use Pre-Exposure Prophylaxis Among Latino Sexual Minority Men in Miami, Florida: A Network Autocorrelation Model

Despite the availability of pre-exposure prophylaxis (PrEP), Latino sexual minority men (LSMM) continue to experience disparities in PrEP uptake and subsequently, HIV vulnerability. Social network norms are an underutilized solution to increase PrEP uptake. We used a peer influence model (network autocorrelation model) to examine the role of social network descriptive norms (i.e., actual behaviors) surrounding PrEP use. A total of 11 sociocentric networks of 13 friends (<i>n</i> = 143 LSMM) were recruited into our study from 2018 to 2019 in South Florida. Most participants were in PrEP pre-contemplation (<i>n</i> = 44), and almost one-third of our sample were using PrEP (<i>n</i> = 38). Three network autocorrelation models were estimated using an empirically informed Bayesian analysis. We found a positive association between participants' Motivational PrEP Cascade (MPC) position and their network members' (friends') cascade position based on three different measures of connection even when accounting for PrEP knowledge: friendship (<i>ρ</i> = 0.22; 95% CI^a = 0.01-0.42), emotional closeness (<i>ρ</i> = 0.24; 95% CI = 0.03-0.44), and frequency of interaction (<i>ρ</i> = 0.22; CI = 0.03-0.42). Our findings highlight that an individual's progress in the MPC may be influenced by their network members' progress in the MPC, suggesting that LSMM using PrEP may serve as role models to their peers for PrEP use due to descriptive norms. Our findings further suggest that PrEP interventions for LSMM along the MPC can be implemented at the social network level.