4C4 ”Sexual Age” and Sexual Risk Behaviors Among Men Who Have Sex with Men

Thursday, September 22, 2016: 3:45 PM
Grand Ballroom
Cara E. Rice, PhD, MPH1, Sara A. Vasilenko, PhD2, Joshua G. Rosenberger, PhD, MPH2 and Stephanie T. Lanza, PhD2, 1Department of Biobehavioral Health, The Methodology Center, Pennsylvania State University, University Park, PA, 2Pennsylvania State University

Background:  Men who have sex with men (MSM) in the United States (US) are particularly vulnerable to HIV and other sexually transmitted infections (STI). While age is frequently examined as a potential predictor of behavior and HIV/STI risk, “sexual age” (SA) or time since first having sex with men may be more predictive of behavioral patterns than chronological age.

Methods:  We analyzed survey data from 17,949 men (82% white; 81% gay; median age=33) recruited from a US website for men seeking social or sexual interactions with other MSM. SA was defined as the time in years since first oral or anal sex with a male partner (median SA=13 years). We used the time-varying effect model (TVEM) to flexibly estimate the rates of anal sex, enema use, and group sex as a nonparametric function of SA. To better understand the impact of SA among men of different ages, models were run separately for three age groups (18-30, 31-50, 51+). 

Results:  For all age groups, the rate of engagement in anal sex was highest in the first year after a man’s first same-sex sexual experience.  Among men aged 18-30, the rate of anal sex was highest initially then declined steeply in the first three years. In contrast, enema use among men increased steadily as a function of SA for all age groups. Among younger men, the rate of engaging in group sex increased gradually across SA; men over 50 with young SA had significantly higher rates of group sex.

Conclusions:  These findings suggest that sexual age may be an important predictor of sexual behaviors and, potentially, HIV/STI acquisition. Further study is needed to understand the trajectory of sexual behavior that occurs after first same-sex sexual experience among MSM.