August 6, 2008
OraSure Technologies' OraQuick Advance Rapid HIV 1/2 Antibody Test produced more false positive results than expected when administered to patients in the emergency department at Brigham and Women's Hospital, according to a study published this week in the Annals of Internal Medicine, the Washington Post reports.
For the study, Rochelle Walensky, a physician at the hospital, and colleagues over eight months administered the OraQuick test to 854 ED patients who did not know their HIV status.
According to the study, 31 patients tested positive initially; however, only five were found to be HIV-positive after undergoing a test to confirm the results of the OraQuick test. Previous studies have reported similar rates of false positives, the Post reports.
Instead of replacing the OraQuick test with a more accurate rapid test, the researchers learned to anticipate a higher number of false positives and act accordingly. Walensky said that although blood tests are more accurate, patients are less willing to receive a blood test than the OraQuick test, adding that "more people accept HIV testing" with the OraQuick test "than otherwise might."
Walensky said that physicians administering the OraQuick test should be prepared to handle potential false positives and discuss the possibility of a false positive with patients. Physicians also should ensure that all initial positive results are followed with a blood test.
According to the Post, 13% of EDs offered the OraQuick test in 2006, but that percentage likely has increased. Each hospital determines its own testing strategy, according to Bernhard Branson, a CDC epidemiologist and lead author of the 2006 guidelines that called for HIV testing in EDs. Christopher Pilcher, associate professor of medicine in the HIV/AIDS division at the University of California-San Francisco, said, "If we're going to ... start widely testing in a population where there hasn't been wide testing before, we're going to have to be really careful to have accurate and robust testing" (Ganguli, Washington Post, 8/5).
An abstract of the study is available online.
Reprinted with permission from kaisernetwork.org. You can view the entire Kaiser Daily HIV/AIDS Report, search the archives, or sign up for email delivery at www.kaisernetwork.org/dailyreports/hiv. The Kaiser Daily HIV/AIDS Report is published for kaisernetwork.org, a free service of the Kaiser Family Foundation, by The Advisory Board Company. © 2008 by The Advisory Board Company and Kaiser Family Foundation. All rights reserved.