Optimizing long-acting injectable PrEP strategies for sexual minority men who use methamphetamine - SUMMARY This exploratory R21 proposal addresses a critical gap in HIV prevention by identifying preferences and care components to optimize the delivery of long-acting injectable (LAI) PrEP for sexual minority men (SMM) who use methamphetamine (meth). In the U.S., SMM are disproportionately affected by HIV, exacerbated by the resurging meth epidemic. SMM who use meth have a quadrupled risk of HIV seroconversion, and those who use stimulants face a 3-fold risk of disengagement from PrEP care and 5-fold risk of sub-optimal oral PrEP adherence. Bimonthly LAI PrEP has proven more effective than daily oral PrEP, and is generally preferred by people who inject drugs. LAI PrEP could be well-received and a game-changer to improve adherence and reduce HIV risk. However, there is a lack of data that has systematically assessed acceptable and preferred strategies to maximize LAI PrEP implementation for SMM who use meth. Our study leverages the participant pool from the ongoing AMETHST U.S. national cohort of SMM who use meth (UH3AI169652, Grov/Carrico) to first qualitatively identify modifiable care options for LAI PrEP use, followed by a large Discrete Choice Experiment (DCE) to quantitatively assess care preferences. Aim 1: Conduct rapid qualitative interviews to develop the DCE. We will interview 30-36 SMM who use meth (10-12 Black, 10-12 Latinx, and 10-12 others) and 20-30 healthcare providers with diverse experiences (e.g., LAI PrEP implementation experience, primary care or specialized clinic providers, and PrEP educators/navigators). Open-ended questions will gather insights on familiarity and preferences for LAI PrEP delivery, barriers and facilitators, healthcare settings and providers, and social, behavioral, and practical considerations. These insights will help develop DCE attributes and levels and inform choice architecture for testing. Aim 2: Elicit the preferred choice architecture for LAI PrEP care delivery using a rigorous DCE among a sample of 600 SMM who use meth, stratified by race/ethnicity: 200 Black, 200 Latinx, and 200 others. Plus, we will collect additional data on demographics, risk behaviors (e.g., sexual practices, current meth/substance use), and LAI PrEP experiences. After pilot testing the DCE, we will recruit participants for this new study from the ongoing AMETHST cohort (an available participant pool of 2,820 HIV-negative SMM who use meth, 56.5% persons of color), n = 600 of whom will complete an online DCE (via Sawtooth Software) and survey (via Qualtrics). Hierarchical Bayesian regression models will evaluate utilities for each attribute level and determine the relative importance of attributes among diverse SMM who use meth subgroups (e.g., race/ethnicity, rural/urban). Impact: This timely R21 developmental study will generate critical insights on care preferences among diverse subgroups of SMM who use meth to inform LAI PrEP implementation in the U.S., providing actionable data to guide targeted, scalable strategies for novel prevention products and delivery systems, ultimately reducing HIV incidence in this highly affected population.