Developmental Change in the Effects of Sexual Partnership Characteristics on Sexual Risk Behavior in Young Men Who Have Sex with Men

Background Young men who have sex with men (YMSM) are the only group in which rates of new HIV infections are increasing in the U.S. Partner characteristics (e.g., sexual partner age) and relationship factors (e.g., serious/casual) have an important impact on HIV risk, but analyses have not modeled developmental change in these effects over time. Methods: Data were taken from 118 YMSM enrolled in Project Q2, a longitudinal study of lesbian, gay, bisexual and transgender youth with 4 years of follow-up (developmental age range 16-25). Participants reported on their 3 most recent sexual partners during the 6 months before each assessment, as well as details regarding partner and relationship characteristics. Analyses were conducted using Hierarchical Linear Modeling.  Results: Various partner and relationship characteristics were longitudinally associated with likelihood of unprotected anal intercourse (UAI), including serious (vs. casual) partnerships (ERR=12.50), forced sex (ERR=2.04), physical violence (ERR=1.88), and larger partner age differences (ERR=1.18). In terms of developmental change, the positive associations between several partnership factors and UAI increased with participant age, including the effects of serious (vs. casual) partnerships, forced sex, physical violence, partner age difference, and meeting partners online.  Conclusions: Our novel analysis of developmental change in the effects of partnership characteristics on UAI indicates that the impact of these variables on HIV risk increases substantially from adolescence into emerging adulthood. Findings suggest that couples-based interventions may have a profound impact on HIV risk and should address safer sex options in serious relationships, partner violence, and risks of age discordant relationships.