Perceived versus calculated HIV risk: Implications for Pre-exposure prophylaxis uptake in a randomized trial of men who have sex with men.

Background: Inaccurate HIV risk perception by men who have sex with men is a barrier to HIV prevention. Providing information about objective HIV risk could improve pre-exposure prophylaxis (PrEP) uptake. Methods: PrEP Accessibility Research & Evaluation 2 (PrE-PARE2) was a randomized controlled trial of men who have sex with men to determine whether an objective risk score affects future PrEP uptake. Participants completed a baseline survey to assess demographics, risk behaviors, and HIV self-perceived risk (SPR). The survey generated a calculated HIV risk (CalcR) score, estimating HIV risk based on reported condomless anal intercourse and sexually transmitted infections, and was provided to individuals in the intervention arm. Participants were contacted 8 weeks later to determine whether they initiated PrEP. Results: Of 171 participants (median age 32 years; 37% Hispanic or non-Hispanic Black; median 5 sexual partners in the past 6 months), 81% had heard of PrEP, and 57% believed they were good PrEP candidates. SPR had poor agreement with CalcR (kappa = 0.176) with 38% underestimating their HIV risk. At week 8, only 14 of 135 participants had initiated PrEP with no difference between arms (CalcR 11%, control 10%, P > 0.99). The most common reason for not starting PrEP was low HIV risk perception. There was a relative decrease in SPR over time (P = 0.06) but no difference between arms (P = 0.29). Conclusion: Providing an objective HIV risk score alone did not increase PrEP uptake. HIV testing performed at testing sites may be a crucial time to correct misperceptions about risk and initiate same-day PrEP, given enthusiasm for PrEP on the testing day to facilitate greater uptake.