Pre-Exposure Prophylaxis (PrEP) Use and Condomless Anal Sex: Evidence of Risk Compensation in a Cohort of Young Men Who Have Sex with Men
Young men who have sex with men (YMSM) are disproportionately impacted by HIV. Pre-exposure prophylaxis (PrEP) is highly effective at preventing HIV acquisition. It remains unclear if PrEP use increases rates of condomless sex (i.e., risk compensation), which may increase risk of infection if PrEP adherence is not optimal. This study aimed to examine whether PrEP use and PrEP adherence were associated with change in sexual risk behaviors in a large longitudinal cohort of YMSM reporting on multiple sexual partnerships over time. Method: Data came from the first three visits of an ongoing cohort study of YMSM in Chicago (analytic N=953; 14.1% HIV-positive at baseline). Participants reported up to four sexual partnerships at each visit, including sexual behavior, PrEP use and PrEP adherence within partnerships. Results: YMSM reported higher rates of receptive condomless anal sex (CAS) in partnerships during which they were on PrEP compared to those when they were not on PrEP. This association was consistent across both HIV-negative and HIV-positive participants reporting on partnerships with perceived HIV-negative/unknown and HIV-positive partners. The rate of receptive CAS was higher in PrEP non-adherent partnerships compared to non-PrEP partnerships. The rate of receptive CAS was higher in PrEP non-adherent than adherent partnerships, but this was not statistically significant. Conclusions: These analyses provide compelling data suggesting that YMSM are engaging in risk compensation when on PrEP. If rates of receptive CAS are highest amongst YMSM who are PrEP non-adherent, PrEP as a prevention strategy could fail to curb HIV incidence among YMSM.