Utilizing Laboratory Results to Identify Emergency Department Patients with Indications for HIV Pre-Exposure Prophylaxis.

People newly diagnosed with HIV often have previous contact with health care professionals, often on multiple occasions, including within emergency departments (EDs). Although EDs have become vital partners in routine screening and linkage to care for persons with HIV, ED engagement in HIV prevention efforts, to include HIV risk assessment and pre-exposure prophylaxis (PrEP) referral, are rare. In this study, we electronically queried the hospital electronic health record (EHR) for ED encounters in 2019 and 2020 for patients who screened negative for HIV (N = 26,914) to identify objective evidence of HIV acquisition risk due to recent sexual behavior (sexually transmitted infection screen positive for chlamydia, syphilis, gonorrhea, or trichomoniasis) or recent injection drug practices (urine drug screen positive for heroin, amphetamines, cocaine, or other opiates). In the reviewed period, we identified 1324 patients (4.92%) at sufficient risk to warrant PrEP referral (i.e., PrEP indications), including 304 (22.96%) due to sexual behavior and 1032 (77.95%) due to potential injection drug use. Notably, among adults with PrEP indications regardless of transmission risk group, persons who inject drugs (PWID) represented a significantly larger proportion within our ED cohort as compared with Centers for Disease Control and Prevention (CDC) estimates for the US population (77.95% vs. 6.34%, p < 0.0001). Among adults with PrEP indications due to sexual behavior specifically, women represented a significantly larger proportion within our ED cohort as compared with estimates for the US population (62.17% vs. 16.48%, p < 0.0001). Our results demonstrate that utilizing laboratory results within the EHR may be a simple low-resource option for identifying and engaging PrEP candidates, especially women and PWID.