Willingness to Use Oral and Long-Acting Injectable PrEP in Substance-Using Men who have Sex with Men (SU-MSM) in High HIV Incidence Southern U.S. Cities: A NIDA Clinical Trials Network Study.

In Southern U.S. states with high HIV incidence and low HIV Pre-Exposure Prophylaxis (PrEP) uptake, enhanced efforts to increase interest in and willingness to use PrEP are needed. This implementation survey examined the associations of sociodemographic background, substance use, and sexual risk behaviors with willingness to use daily oral and long-acting injectable (LAI) PrEP among substance using men who have sex with men (SU-MSM). Participants were 225 SU-MSM recruited from sexually transmitted infection (STI) clinics, syringe services programs (SSPs), and substance use treatment programs (SUTPs) in eight Southern U.S. cities. Rates of willingness were high for both daily oral PrEP (78%) and LAI PrEP (66%). In multivariable analyses, distinct factors were associated with willingness towards each. For daily oral PrEP, greater willingness was associated with condomless anal sex, less frequent non-injection opioid use, prior PrEP awareness, and past use of PrEP. For LAI PrEP, greater willingness was associated with Black race, identifying as gay, being single, and higher injection drug use frequency. Lower willingness to use LAI PrEP was associated with higher non-injection opioid use frequency. Findings about willingness to use LAI PrEP, as a relatively newer modality, and greater willingness among Black SU-MSM as a disproportionately HIV-impacted population, are especially important. These findings argue for the necessity to enhance PrEP promotion efforts that distinguish between oral and LAI PrEP and that are specifically tailored to major SU-MSM subgroups in the Southern U.S.