ABSTRACT HIV prevalence among transgender women (TW) in the United States is high (~14%). The best way to reduce HIV incidence in this population is to link TW to HIV pre-exposure prophylaxis (PrEP), which can reduce HIV transmission by up to 86%, with optimal adherence. The FDA approved the first long-acting form of PrEP, injectable cabotegravir (CAB-LA), in late 2021, which has the potential to decrease HIV transmission and increase PrEP adherence among TW. The addition of CAB-LA to available PrEP options necessitates TW and PrEP service providers select the best method (oral vs injectable) for each TW. However, TW have unique concerns about PrEP (e.g., interactions with gender-affirming hormones) and report that patient/provider discussions on this medication are suboptimal. Thus, to inform this shared decision process, the proposed study builds on formative work by developing and pilot-testing “WePrEP,” a PrEP-focused bilingual digital shared decision-making tool (SDMT), tailored to diverse English- and Spanish-speaking TW and PrEP service providers. WePrEP will support communication between TW and PrEP service providers as they identify the ideal PrEP product for each TW and discuss associated adherence strategies by cuing conversations on TW's unique PrEP needs/concerns and presenting pertinent information that is culturally relevant and tailored to this population. To develop and test WePrEP, we will partner with the Mile High Behavioral Healthcare Transgender Center of the Rockies, a Denver-based transgender-serving organization. We will use McNulty et al.'s adapted Shared Decision-Making Model for TW to guide the iterative participatory design process we will use with a group of racially/ethnically diverse TW and PrEP service providers, to develop WePrEP; we will begin this process using prototypes created from preliminary data (Aim 1a). We will then rigorously assess the usability of WePrEP via simulated patient/provider discussions (Aim 1b). Next, we will pilot test WePrEP in a randomized controlled trial (RCT; N=69 TW) with 2:1 randomization. In the RCT, PrEP service providers (N=4, of which n=1 is bilingual) will use WePrEP with intervention TW to select CAB-LA or oral PrEP and discuss adherence. Other providers (N=2, of which n=1 is bilingual) will give control TW a standard of care explanation of PrEP (CDC recommendations) to help them make their PrEP choice. TW will be referred to Sheridan Health Services to start PrEP. We will assess primary (feasibility; acceptability) and secondary (potential mechanisms of action of WePrEP; preliminary impact) outcome measures using validated scales and rigorous qualitative methods (Aims 2, 3). By creating a bilingual digital SDMT to enhance communication between TW and PrEP service providers as TW choose their ideal PrEP modality, our project is likely to make a widespread and lasting impact on TW's uptake and adherence to PrEP. Our application responds to NOT-MH-21-105, Research digital Advancing Health Communication on HIV Prevention, Treatment, and Cure. Our product is a rigorously designed, pilot-tested, bilingual, SDMT, suitable for use with diverse TW, that will test for efficacy in a larger, longer R01-funded RCT.

NARRATIVE There are now two forms of HIV pre-exposure prophylaxis (PrEP) available (oral PrEP and long-acting injectable cabotegravir; CAB-LA), requiring TW patients and PrEP service providers (e.g., navigators, nurses, physicians) to work together to choose between these products. The intentional and informed use of digital tools can enhance clinical communication and shared decision-making; yet few digital shared decision-making tools (SDMT) tailored to TW exist, and none are PrEP-focused. The proposed study builds on formative work by further developing and pilot testing our existing prototype of a PrEP-focused bilingual (English/Spanish) digital SDMT called, “WePrEP,” that is tailored to diverse TW and PrEP service providers and supports shared decision- making regarding selecting an appropriate PrEP method and reviewing corresponding adherence strategies.