Revising Expectations from Rapid HIV Tests in the Emergency Department

5 August 2008 | Volume 149 Issue 3 | Pages 153-160

Background: Expanded HIV screening efforts in the United States have increased the use of rapid HIV tests in emergency departments. The reported sensitivity and specificity of rapid HIV tests exceed 99%.

Objective: To assess whether a reactive rapid oral HIV test result correctly identifies adults with HIV infection in the emergency department.

Design: Diagnostic test performance assessment within the framework of a randomized, clinical trial.

Setting: Brigham and Women's Hospital emergency department (Boston, Massachusetts) from 7 February to 1 October 2007.

Patients: 849 adults with valid rapid oral HIV test results.

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 enzyme-linked immunoassay, Western blot, and plasma HIV-1 RNA testing for confirmation.

Measurements: Specificity and positive likelihood ratio.

Results: 39 patients had reactive results (4.6% [95% CI, 3.2% to 6.0%]). On confirmation, 5 patients were HIV-infected (prevalence, 0.6% [CI, 0.1% to 1.1%]) and 26 were non–HIV-infected (8 patients declined confirmation). The estimated rapid test specificity was 96.9% (CI, 95.7% to 98.1%). Sensitivity analyses of the true HIV status of unconfirmed cases and test sensitivity resulted in a positive likelihood ratio of 8 to 32. Western blot alone as a confirmation test provided conclusive HIV status in only 50.0% (CI, 30.8% to 69.2%) of patients at first follow-up. The addition of HIV-1 RNA testing to the confirmation protocol improved this rate to 96.2% (CI, 88.8% to 100.0%).

Limitation: Test sensitivity cannot be assessed because nonreactive OraQuick test results were not confirmed.

Conclusion: Although patients with a reactive oral OraQuick HIV screening test in the emergency department had an 8- to 32-fold increased odds of HIV infection compared with the pretest odds, the specificity of the test was lower than anticipated.

Editors' Notes Context Few studies have examined performance characteristics of rapid oral HIV testing. Contribution In this study, 39 of 849 adults who visited an urban emergency department had a reactive rapid oral HIV test. Confirmatory tests showed that 26 of the 39 patients were not HIV-infected (specificity, 96.9% [95% CI, 95.7% to 98.1%]). Patients with reactive tests had an 8- to 32-fold greater odds of HIV infection relative to the pretest odds. Caution Test sensitivity was not assessed because patients with nonreactive results did not receive confirmatory tests. Implication Rapid oral HIV testing can help identify patients with increased odds of HIV infection. —The Editors

 

Author and Article Information

From Brigham and Women's Hospital, Massachusetts General Hospital, Harvard Medical School, and Partners AIDS Research, Boston, Massachusetts.

Acknowledgment: The authors thank the co-investigators and staff of the USHER Trial, including Carrie Braverman, Susan Larrabee, Regina Mikulinsky, Paul Sax, and Elizabeth Wright. They also thank the faculty and staff of Brigham and Women's Hospital emergency department for their participation in the USHER Trial and for their dedication to the identification of undiagnosed HIV infection, especially the emergency service assistants and focus group members. Finally, they thank Kenneth A. Freedberg, MD, MSc, and A. David Paltiel, PhD, for critical review of the manuscript; Doug Owens, MD, for advice and study critique; and Mariam Fofana for technical assistance.

Grant Support: By the National Institute of Mental Health (R01 MH073445, R01 MH65869) and the Doris Duke Charitable Foundation, Clinical Scientist Development Award (Dr. Walensky).

Potential Financial Conflicts of Interest: None disclosed.

Reproducible Research Statement: Study protocol, statistical code, and data set: Available from Dr. Walensky (e-mail, rwalensky{at}partners.org).

Requests for Single Reprints: Rochelle P. Walensky, MD, MPH, Massachusetts General Hospital, 50 Staniford Street, 9th Floor, Boston, MA 02114; e-mail, rwalensky{at}partners.org.

Current Author Addresses: Dr. Walensky: Division of General Medicine, Massachusetts General Hospital, 50 Staniford Street, 9th Floor, Boston, MA 02114.

Drs. Arbelaez and Walls: Department of Emergency Medicine, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115.

Mr. Reichmann and Drs. Katz and Losina: Orthopaedic and Arthritis Center for Outcomes Research, Brigham and Women's Hospital, 75 Francis Street, BC 4-4016, Boston, MA 02115.

Mr. Block: Partners AIDS Research Center, 149 13th Street, Room 5234k, Charlestown, MA 02129.

Mr. Dooley, Mr. Hetland, Mr. Kimmel, and Ms. Solomon: Department of Emergency Medicine, USHER Trial Research Assistant, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115.

Author Contributions: Conception and design: R.P. Walensky, E. Losina.

Analysis and interpretation of the data: R.P. Walensky, W.M. Reichmann, J.N. Katz.

Drafting of the article: R.P. Walensky, C. Arbelaez, E. Losina.

Critical revision of the article for important intellectual content: R.P. Walensky, C. Arbelaez, W.M. Reichmann, R.M. Walls, J.N. Katz, B.L. Block, M. Dooley, A. Hetland, S. Kimmel, J.D. Solomon, E. Losina.

Final approval of the article: R.P. Walensky, C. Arbelaez, W.M. Reichmann, J.N. Katz, B.L. Block, M. Dooley, A. Hetland, S. Kimmel, J.D. Solomon, E. Losina.

Provision of study materials or patients: R.P. Walensky, R.M. Walls.

Statistical expertise: W.M. Reichmann, J.N. Katz, E. Losina.

Obtaining of funding: R.P. Walensky.

Administrative, technical, or logistic support: R.M. Walls, B.L. Block, M. Dooley, A. Hetland, S. Kimmel, J.D. Solomon.

Collection and assembly of data: R.P. Walensky, W.M. Reichmann, B.L. Block, M. Dooley, A. Hetland, S. Kimmel, J.D. Solomon.

ClinicalTrials.gov registration number: NCT00502944.

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