Optimizing Evidence-based HIV Prevention Targeting People Who Inject Drugs on PrEP

Participants will be randomized to one of 16 conditions. In addition to receiving the Core Components of the CHRP behavioral intervention, participants will receive one of the sixteen combinations of four compensatory components that show promise in terms of enhancing the ability to process and utilize HIV prevention content (see conceptual figure above), and that are not currently part of CHRP. The Attention Component includes: (a) Increasing frequency of sessions (more than once per week); (b) Distributed practice (spreading out information across sessions); (c) More structured sessions (well‐organized objectives shared with patients); (d) Introducing new information during closure (foreshadow content of next session). The Executive Function Component includes the following strategies: (a) Associating behavior with situational cues (anticipate risky situations); (b) Linking actions to a triggering cue (storytelling techniques using imagery); (c) Planning (identify and organize steps required to meet goal) and (d) Valuing future events (recognize the benefits of drug treatment). Similarly, the Memory Component involves: (a) Memory aids (reminders and cues to be used between sessions); (b) Summarizing/reiterating information (frequent review throughout sessions); (c) Prospective memory (emphasize routine, develop cues, elaborate on positive behaviors); and (d) Environmental engineering (prepare for adverse events). Lastly, the Information Processing Component includes: (a) Mixed methods of presentation (verbal, visual, and hands‐on); (b) Simple language (clear, concrete examples aligned with health literacy level); (c) Present content slowly (allow extra time for responses); and (d Immediate feedback following assessment (oral/ written).Of particular note, the investigators are using this framework to examine all combinations of these components (rather than merely testing all four) to promote ecological validity and future implementation. Specifically, our approach will help determine the most resource‐efficient intervention, as there are many barriers to adding components to standard of care in these clinical settings. For example, if components targeting only two domains can produce equivalent outcomes as components targeting four, the former would be identified as preferred