Cannabis and alcohol co-use and HIV biomedical intervention engagement among Black sexual/gender minority (BSGM) people: A day-level analysis.

Introduction: Cannabis and alcohol are the most frequently used substances among Black sexual/gender minority (BSGM) people and co-use of these substances is surging. Little work exists on the association of cannabis/alcohol co-use with HIV prevention and care engagement in this population. We examined daily associations of cannabis/alcohol co-use with pre-exposure prophylaxis (PrEP) and antiretroviral (ARV) medications use, in the context of hazardous alcohol and cannabis use, among BSGM.

Methods: Daily use of cannabis, alcohol, and PrEP/ARV were assessed via 14-day ecological momentary assessment (EMA) in the Neighborhoods and Networks Part 2 (N2P2) cohort study of BSGM in Chicago (2022-2024). Generalized estimating equations models were used to examine day-level associations between cannabis/alcohol co-use and following day PrEP/ARV use.

Results: Across 5,729 days for 521 participants with ≥1 EMA responses, cannabis/alcohol co-use, cannabis-only use, alcohol-only use, and no substance use occurred on 19.8%, 36.5%, 6.3%, and 34.9% days, respectively. Among participants who reported hazardous alcohol use (AUDIT≥8), on cannabis-only days, participants were more likely to report following day PrEP/ARV use (aRR=1.54; 95% CI=1.00, 2.38). Among participants with no hazardous alcohol use, alcohol-only use day was associated with greater following day PrEP/ARV use (aRR=1.34; 95% CI=1.02, 1.76). Cannabis/alcohol co-use was not associated with PrEP/ARV use, regardless of hazardous alcohol or cannabis use status.

Conclusions: Heterogeneity exists regarding associations between cannabis/alcohol co-use and PrEP/ARV use among BSGM, depending on individuals' hazardous alcohol use status. Future research should collect fine-grained contextual data on cannabis/alcohol co-use to examine mechanisms by which co-use influences HIV care engagement.