Willingness to Prescribe PrEP to Bisexual Men Depends on Genders of Their Past Partners: A Study of Medical Students in the USA.

Bisexual men are at increased risk for HIV compared to heterosexual men but unlikely to use pre-exposure prophylaxis (PrEP). Given that biases may influence whether bisexual men are prescribed PrEP, we examined whether medical students' decision-making was influenced by the genders of a bisexual male patient's partners. Medical students (N = 718) were randomized to one of nine conditions where they answered questions about a bisexual male patient after reviewing his electronic medical record. We manipulated the gender of his current partner (none, male, female) and the genders of his past partners (male, female, both). Current partners were described as living with HIV and not yet virally suppressed, past partners were described as being of unknown HIV-status, and condom use was described as intermittent with all partners. When the patient was not in a current relationship, perceived HIV risk and likelihood of prescribing PrEP were lowest if he only had female partners in the past. When he was in a current relationship, perceived HIV risk and likelihood of prescribing PrEP did not differ based on current or past partners' genders. In addition, identification as a PrEP candidate, perceived likelihood of adherence, and perceived likelihood of engaging in condomless sex if prescribed were lower when the patient was not in a current relationship. Medical students appropriately prioritized the status of the partner living with HIV, but their decision-making was influenced by past partner genders when the patient was not in a current relationship. Medical students may require additional education to ensure they understand PrEP eligibility criteria and make decisions based on patients' individual presentations.