Evaluation of an Electronic Algorithm for Identifying Cisgender Female Pre-Exposure Prophylaxis Candidates

We previously developed an electronic medical record-based algorithm for identifying patients at risk for HIV in the emergency department (ED). The aim of this study was to evaluate the performance of the HIV risk algorithm for identifying cisgender women with a pre-exposure prophylaxis (PrEP) indication. To retrospectively evaluate the HIV risk algorithm, we identified cisgender women with HIV diagnosed in the ED and retrospectively calculated the HIV risk algorithm output. To prospectively validate the algorithm, we surveyed cisgender women seeking care in the ED regarding behavioral risks for HIV. We prospectively determined whether the algorithm identified them as PrEP candidates. In the retrospective evaluation, 9.4% (2/21) of women with incident HIV infection were identified as at risk for HIV by the algorithm. In the prospective evaluation, 24% (59/245) of women who completed the survey had a PrEP indication based on self-report of behavioral risk factors for HIV. The sensitivity of the algorithm for identifying cisgender female PrEP candidates was 10%, and the specificity was 96%. PrEP indications missed by the electronic algorithm included condomless sex in a high HIV prevalence area, multiple sex partners, male partners who have sex with men, and recent bacterial sexually transmitted infections diagnosed at outside clinics. An electronic algorithm to identify PrEP candidates in the ED has low sensitivity for identifying cisgender women with PrEP indications. More research is needed to identify electronic data that can improve the algorithm sensitivity among cisgender women.