Substance Use and Healthcare Utilization Across the Pre-Exposure Prophylaxis (PrEP) Care Cascade among Black and Latino Men Who Have Sex with Men.

Despite the documented efficacy of pre-exposure prophylaxis (PrEP) for HIV prevention, large disparities in uptake and adherence exist among Black and Latino/Hispanic men who have sex with men (BLMSM). Limited data exists among BLMSM on the impact of substance use at different stages of the PrEP Care Cascade. We examined the ways substance (alcohol, cannabis, other drug) use is related to PrEP experiences across the PrEP Care Cascade (PrEP aware/no use; PrEP use/discontinuation; PrEP use/adherent). We utilized data from a national sample of 908 BLMSM (M = 25.17, range: 18-29), collected between February and October 2020. We found that heavier alcohol use, more other drug (e.g., cocaine) use, more participant healthcare utilization, and higher number of partners across all measures of substance use were separately associated with a lower likelihood of being aware of PrEP. These same factors were also associated with a higher likelihood of PrEP adherence. Conversely, only cannabis use was associated with discontinuation of PrEP use. While we confirm some earlier findings (i.e., alcohol use is associated with both PrEP discontinuation and PrEP use), we newly identify cannabis as a barrier to the adherence of PrEP. Our findings highlight the need for improved PrEP interventions to increase awareness among BLMSM with substance use who are among the most at-risk for HIV infection.