Effectiveness of Rapid HIV Screening Methods in Urban Emergency Departments

Early identification of undiagnosed HIV infection remains a critical public health priority. In the United States, approximately 250,000 HIV-infected individuals remain undiagnosed and 50,000 new infections occur annually, despite several substantial HIV-related public health initiatives. Although HIV testing is an important intervention, controversy still exists as to how it should be implemented.

In 2006, the Centers for Disease Control and Prevention (CDC) recommended nontargeted opt-out HIV screening in clinical settings where the undiagnosed prevalence was ≥0.1%. Emergency departments (EDs) have been a major focus of these recommendations, prompted by the fact that over 120 million ED visits occur annually in the United States, they serve large proportions of underserved patients, and are the most common site of missed diagnostic opportunities for HIV infection. In contrast, in 2007 the United States Preventive Services Task Force recommended targeted HIV screening (i.e., testing high-risk subpopulations) as the principal approach to HIV testing because insufficient evidence existed to support the CDC recommendations.

Led by Jason Haukoos, MD, MSc, the research team has pioneered investigations in this area since 2004, recently publishing the largest clinical trial to date, concluding that nontargeted opt-out rapid HIV screening in the ED was associated with a small increase in number of newly-identified HIV-infected patients when compared to diagnostic testing (i.e., testing based on clinical signs or symptoms) by physicians. The investigators also recently developed the Denver HIV Risk Score (DHRS), the first multivariable tool to estimate risk of HIV infection. The DHRS combines 3 demographic and 5 behavioral characteristics, and classifies patients into distinct strata with increasing HIV prevalence.

To build on this work, the investigators propose the following specific aims: (1) to evaluate and compare the effectiveness of 3 rapid HIV screening strategies when fully-integrated into ED care; (2) to measure and compare programmatic costs of each HIV screening strategy; and (3) to measure and compare ED operational processes of each HIV screening strategy. In doing so, the investigators will perform a multi-center prospective randomized control trial to test the following hypotheses: (1) targeted rapid HIV screening using the DHRS to identify high-risk patients is significantly associated with new HIV diagnoses when compared to traditional targeted rapid HIV screening and nontargeted rapid HIV screening; (2) enhanced and traditional targeted rapid HIV screening is more cost effective per newly-identified patient than nontargeted rapid HIV screening; and (3) enhanced targeted rapid HIV screening is associated with non-inferior ED process metrics and crowding when compared to traditional targeted screening or nontargeted screening.

To accomplish these aims, the investigative team will conduct: (1) a prospective randomized controlled "pragmatic" clinical effectiveness trial in the EDs at Denver Health Medical Center (Denver, CO), Alameda County Medical Center (Oakland, CA), Johns Hopkins Hospital (Baltimore, MD), and the University of Cincinnati Medical Center (Cincinnati, OH); and (2) nested observational studies to evaluate programmatic costs and operational metrics between the 3 rapid HIV screening strategies and using newly-diagnosed HIV infection as the primary outcome.