Abstract
BACKGROUND: Alcohol use is linked with HIV-associated sexual behaviors and new HIV infections, and individuals who drink alcohol may benefit from Pre-Exposure Prophylaxis (PrEP) to prevent HIV. We evaluated the prevalence and correlates of current PrEP use and missed PrEP doses due to alcohol. METHODS: We included 604 HIV-negative participants (i.e., those eligible for PrEP) in San Francisco. Primary outcomes were current PrEP use and missed PrEP doses due to alcohol use in the past 3 months. Modified Poisson regression models with robust standard errors were fitted separately for each exposure while controlling for age, gender, and race/ethnicity. RESULTS: We enrolled a diverse sample comprising 56 % cisgender male, 42 % cisgender female, and 2 % transgender participants, and 33 % who were sexual minority men (SMM). Mean age was 39.45 years (SD=12.50). Current PrEP use was 21 % and missed PrEP doses due to alcohol were reported by 51 % of the sample who used PrEP. Factors associated with greater odds of PrEP use overall include: having anal intercourse while under the influence of alcohol (14.57 [7.17,29.60], p < 0.001) and any STIs (1.94 [1.40,2.69], p < 0.001), all in the past 3 months. Each additional day of cocaine use was associated with lower odds of PrEP use (0.93 [0.89,0.98], p = 0.01). Condomless anal intercourse under the influence of alcohol were associated with greater odds of missing PrEP doses (17.47 [7.05-43.30], p < 0.001). Among SMM, cocaine use was associated with lower odds of PrEP use (0.91 [0.86-0.97], p = 0.03, while having condomless vaginal intercourse while under the influence of alcohol was associated with missing PrEP doses due to alcohol (2.07 [1.11,3.82], p = 0.02) in the last 3 months. CONCLUSIONS: PrEP prevalence is low, with more than half the participants reporting missed PrEP doses due to alcohol use, which was associated with engaging in sexual activity while under the influence of alcohol. Furthermore, PrEP use is associated with increased alcohol use and recent STIs diagnoses. These findings can help optimize interventions to increase PrEP use and adherence among sexually active adults who drink alcohol, including SMM. Further, the findings also highlight the need for integrating alcohol use interventions into PrEP care.