Differences in HIV Risk Behaviors Between Self-Identified Gay and Bisexual Young Men Who are HIV-Negative.

Young men who have sex with men (MSM) are disproportionately affected by HIV, but it remains unclear whether there are differences in HIV risk behaviors between self-identified gay and bisexual young men. To address this, the current study examined differences in condomless sex and substance use before sex with male partners between self-identified gay and bisexual young men who are HIV-negative. Additionally, we examined differences in HIV risk behaviors with male versus female partners among the bisexual men. We used four waves of data spanning 24 months from a cohort of young MSM ages 16-29. At each wave, participants reported on up to four partners, allowing us to examine within-person associations. Compared to gay men, bisexual men reported more insertive condomless anal sex (CAS) with casual partners, they were more likely to report marijuana use before sex, and they were less likely to report lifetime HIV testing and PrEP use. Alcohol and marijuana use before sex were associated with CAS for both gay and bisexual men, but the association between marijuana use and insertive CAS was stronger for bisexual men. Bisexual men reported more condomless sex with female partners compared to male partners, but this was not significant after accounting for alcohol and marijuana use. Bisexual men were more likely to report alcohol and marijuana use with female partners compared to male partners, but both alcohol and marijuana use were associated with condomless sex regardless of partner gender. Findings support the need for tailored HIV prevention for self-identified bisexual men to address their lack of preventive behaviors, their increased engagement in certain risk behaviors with male partners, and their engagement in risk behaviors with female partners.