Role of Social and Sexual Network Factors in PrEP Utilization Among YMSM and Transgender Women in Chicago.

Despite demonstrated efficacy, uptake of HIV pre-exposure prophylaxis (PrEP) remains low, particularly among high-risk demographics such as transgender women, Black men who have sex with men (BMSM), and young MSM (YMSM). Research thus far has largely focused on individual factors that may impede PrEP uptake in these demographics, leaving social network factors relatively unexplored. The present study used data collected from participants within RADAR, a longitudinal cohort study in Chicago focused on understanding the individual, dyadic, network, social, and biologic factors associated with HIV infection within YMSM. Of the 906 study participants who did not report an HIV diagnosis at baseline, 7.0% reported using PrEP in the prior 6 months. Recent PrEP use was associated with both individual-level (age and gender) and network-level factors (mean relationship strength, sexual network degree, etc.). These findings highlight the need to expand beyond focusing on individual-level drivers of PrEP uptake, as well as changing our understanding of who is most important within a network (centrality vs. strength of weak ties). Future work is needed to determine whether variables associated with PrEP uptake are similarly connected to PrEP adherence.