Study protocol of a randomized controlled trial to assess the efficacy of the "PrEPare for Work" intervention to enhance PrEP uptake and optimize adherence for HIV prevention among male sex workers in the U.S.

Background: Male sex workers (MSWs), specifically cisgender men who exchange sex for money, goods, drugs, or other items of value with other cisgender men, are at high risk for HIV infection. Compared to men not engaged in sex work, MSWs are more likely to engage in frequent condomless sex with paying and non-paying sexual partners. While MSWs are often included as a subgroup of gay and bisexual men, data show that a large proportion identify as heterosexual; additionally, most MSWs do not identify as "sex workers." This places MSWs in a unique position where they may not engage with traditional HIV prevention programs, and when they do, they may not feel comfortable, leading to poor retention. Thus, HIV prevention interventions that address MSWs' unique life circumstances and provide support in exploring their sexual health options are needed.

Methods: In this protocol paper, we describe the design and procedures for a National Institute of Health-funded, randomized controlled trial testing the efficacy of "PrEPare for Work,"- a theory-based, manualized PrEP uptake and adherence intervention for MSW - using a 2-stage randomization design. Stage 1: MSWs are equally randomized to receive either the "PrEPare for Work Stage 1 intervention" (strength-based case management and facilitated PrEP linkage) or Standard of Care (SOC) to evaluate successful PrEP uptake (prescription filled) within two months post-randomization. Stage 2: Those who initiate PrEP are then equally re-randomized to receive either the "PrEPare for Work Stage 2 intervention" (1-on-1 skills training, problem-solving, and motivational interviewing adherence counseling and personalized, daily text message reminders) or SOC to assess adherence (Tenofovir concentrations in hair) over 12 months of follow up. Planned analyses will examine intervention efficacy, specific conceptual mediators, and hypothesized moderators.

Discussion: Based on our extensive preliminary research, multi-component, theory-informed interventions targeting this subpopulation of MSWs' unique life circumstances are urgently needed. In this study, we are evaluating whether "PrEPare for Work" can improve PrEP uptake and adherence among MSWs. If this intervention is efficacious, it would be readily disseminated to diverse community organizations that serve MSWs and possibly other community or clinic-based settings.

Trial Registration: ClinicalTrials.gov number NCT05736614, registered February 8, 2023.