Using Nonrapid HIV Technology for Routine, Opt-out HIV Screening in a High-volume Urban Emergency Department

Objective: We implement an opt-out routine screening program in a high-volume, urban emergency department (ED), using conventional (nonrapid) technology as an alternative to rapid HIV tests.

Methods: We performed a retrospective cohort study. Since October 2008, all patients who visited Ben Taub General Hospital ED and had blood drawn were considered eligible for routine opt-out HIV screening. The hospital is a large, publicly funded, urban, academic hospital in Houston, TX. The ED treats approximately 8,000 patients monthly. Screening was performed with standard chemiluminescence technology, batched hourly. Patients with positive screening test results were informed of their likely status, counseled by a service linkage worker, and offered follow-up care at an HIV primary care clinic. Confirmatory Western blot assays were automatically performed on all new HIV-positive samples.

Results: Between October 1, 2008, and April 30, 2009, 14,093 HIV tests were performed and 39 patients (0.3%) opted out. Two hundred sixty-two (1.9%) HIV test results were positive and 80 new diagnoses were made, for an incidence of new diagnoses of 0.6%. There were 22 false-positive chemiluminescence results and 7 indeterminate Western blot results. Nearly half the patients who received a new diagnosis were not successfully linked to HIV care in our system.

Conclusion: Opt-out screening using standard nonrapid technology, rather than rapid testing, is feasible in a busy urban ED. This method of HIV screening has cost benefits and a low false-positivity rate, but aggressive follow-up and referral of patients with new diagnoses for linkage to care is required.