Test-to-PrEP: A Randomized Hybrid Implementation/Effectiveness Trial of a Social Network Strategy to Increase Equitable Reach of HIV Testing and PrEP Information - Abstract/Project Summary For this project, we propose a type 3 hybrid implementation-effectiveness randomized controlled trial (RCT) comparing two strategies that engage the social networks of current PrEP clients from communities with high HIV incidence to extend the reach of HIV self-testing (HIVST) and PrEP. We aim to evaluate the effectiveness, resource needs (including cost) and implementation factors of Test-to-PrEP, a strategy in which current PrEP clients directly distribute HIV self-tests (HIVST) and PrEP resources to their social network contacts, and a comparison social network referral strategy without direct distribution of HIVST. Building on successful pilot testing of the Test-to-PrEP strategy through two Ending the HIV Epidemic (EHE) Supplement Projects, our team, supported by the Florida Department of Health, community partners Prevention305, and the Implementation Science Coordination, Consultation, and Collaboration Initiative (ISC3I), seeks to conduct this trial in Miami-Dade County, Florida—a region with a one of the highest rates of new HIV diagnoses in the United States and an EHE priority areas. The trial encompasses two key components: (1) strategically located sites in priority neighborhoods for HIV prevention, ensuring diverse representation of Latino and Black PrEP client participants, and (2) the use of social networks for disseminating HIVST and PrEP information. Participants (N=320 PrEP client egos) will be recruited at clinic sites, with randomization by clinic block to one of the two social network strategies being evaluated. Utilizing the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework and the Consolidated Framework for Implementation Research (CFIR), the study will assess the reach and implementation of each strategy and identify contextual factors associated with success including cost and resource requirements. Effectiveness will be evaluated based on completion of HIVST among social network alters, changes in PrEP knowledge, and PrEP or HIV treatment initiation. Both strategies aim to overcome structural and socio-cultural barriers by using trusted networks, specifically engaging PrEP clients to provide social network support and resources for accessing PrEP/HIV treatment. Understanding the effectiveness and resource requirements of these two strategies will inform their adoption in other EHE priority areas, contributing significantly to the broader efforts to combat the HIV epidemic.