Another look at Emergency Department HIV screening in practice: no need to revise expectations

BACKGROUND: A recent study reported a lower than expected specificity and positive predictive value of the rapid oral HIV test in the setting of routine emergency department (ED) screening. These results appeared inconsistent with the findings in another urban Emergency Department during the same time period. OBJECTIVE: To compare the specificity and positive predictive vale (PPV) of an oral rapid HIV test used in an ED screening program in Washington DC with that performed in the USHER clinical trial. DESIGN: Period cross-sectional analysis of rapid oral HIV testing conducted in an ongoing HIV screening program emergency department patients. SETTING: The George Washington University Emergency Department (Washington DC) from 7 February to 1 October 2007. PATIENTS: 1,560 adults seen in the ED for non-HIV-related presenting complaints, who participated in the HIV screening program. INTERVENTION: Rapid HIV testing with the OraQuick ADVANCE Rapid HIV-1/2 Antibody Test (OraSure Technologies, Bethlehem, Pennsylvania). Patients with reactive rapid test results were offered Western blot testing for confirmation. MEASUREMENTS: Specificity and positive predictive value for the program were determined. Findings were compared to those found in the USHER trial. RESULTS: Of 1,560 patients screened for HIV, 13 [0.8%, 95% CI 0.38% to 1.28%] had a reactive HIV screening test, and all were confirmed to be positive by Western Blot. The specificity was 100% (95% CI 99.6%-100%). LIMITATION: Since non-reactive tests were not confirmed, the test sensitivity cannot be determined. CONCLUSION: Review of our data conflict with findings from the USHER study surrounding false positive OraQuick HIV screening. Our data suggest that rapid HIV screening protocols implemented in EDs outside of the clinical trial paradigm perform effectively without an excess of false positive results. Compared with other screening tests, HIV rapid screening should remain an essential component of ED practice.