Explaining the Efficacy of Pre-exposure Prophylaxis (PrEP) for HIV Prevention: A Qualitative Study of Message Framing and Messaging Preferences Among US Men Who have Sex with Men.

We investigated message comprehension and message framing preferences for communicating about PrEP efficacy with US MSM. We conducted eight focus groups (n = 38) and n = 56 individual interviews with MSM in Providence, RI. Facilitators probed comprehension, credibility, and acceptability of efficacy messages, including percentages, non-numerical paraphrases, efficacy ranges versus point estimates, and success- versus failure-framed messages. Our findings indicated a range of comprehension and operational understandings of efficacy messages. Participants tended to prefer percentage-based and success-framed messages, although preferences varied for communicating about efficacy using a single percentage versus a range. Participants reported uncertainty about how to interpret numerical estimates, and many questioned whether trial results would predict personal effectiveness. These results suggest that providers and researchers implementing PrEP may face challenges in communicating with users about efficacy. Efforts to educate MSM about PrEP should incorporate percentage-based information, and message framing decisions may influence message credibility and overall PrEP acceptability.