HIV care status and CD4 count among patients identified through an emergency department-based HIV screening program

BackgroundDisengagement from HIV care may impair immune reconstitution and increase the risk of advanced disease and transmission. We evaluated the association between HIV care status and CD4 count among patients identified through a universal emergency department-based HIV screening program.MethodsWe conducted a cross-sectional study of electronic health records from six emergency departments within a single healthcare system in South Broward County, Florida, from July 2018 through February 2024. Adults were offered free HIV combination assay testing. Patients with reactive screening tests were referred for CD4 count and viral load testing. HIV care status was categorized as out of care/refused, in care, linked to care, re-engaged in care, or deceased. Multivariable linear regression examined the association between CD4 count and care status, adjusting for HIV status, demographics, insurance, viral load, and transmission risk.ResultsAmong 828 positive HIV screening tests (positivity rate, 0.6%), 459 patients (55%) met inclusion criteria. The remaining 369 patients (45%) were excluded, primarily because of missing CD4 count data. After adjustment, patients engaged in HIV care had significantly higher CD4 counts than those out of care/refusing care (median CD4, 628 vs 176 cells/mm³; β = 244.6; 95% CI, 48.7-440.6; p = 0.014). Detectable and unknown viral loads were independently associated with lower CD4 counts compared with undetectable viral loads (β = -223.1 and -227.8, respectively; both p < 0.001). Although newly diagnosed patients had lower unadjusted CD4 counts, adjusted analyses demonstrated higher CD4 counts than patients with previously known HIV (β = 149.0; 95% CI, 56.6-241.4; p = 0.002), indicating confounding by care engagement. Excluded patients were similar to included patients except for more frequent unknown HIV transmission risk.ConclusionPatients disengaged from HIV care had substantially lower CD4 counts, suggesting more advanced disease. These findings support universal emergency department-based HIV screening as an opportunity to identify people living with HIV who are out of care and prioritize linkage and retention interventions to improve immune outcomes and reduce onward transmission.