Testing presented as routine: 'opt-out' strategy improves prenatal HIV testing rates

OB/GYN News, Sept 15, 2004

SAN DIEGO -- One Toronto health clinic's use of an "opt-out" strategy for universal HIV testing during pregnancy led to significantly higher acceptance rates of testing than did the "opt-in" strategy practiced in the province of Ontario. Dr. Mark Yudin reported at the annual meeting of the Infectious Diseases Society for Obstetrics and Gynecology.

The finding supports work by other investigators in this area of study who have shown prenatal HIV testing acceptance rates of at least 90% in jurisdictions where an opt-out strategy is the standard of practice, said Dr. Yudin, an obstetrician with the department of ob.gyn. and reproductive infectious disease at St. Michael's Hospital, Toronto.

Two approaches to universal screening for HIV in pregnant women are used in the United States and Canada: opt in and opt out. With an opt-in approach, "testing is offered but is only done after explicit and fairly rigorous informed consent is given by the patient," Dr. Yudin explained.

"With an opt-out approach to testing, testing is presented as a routine test and is only omitted if the patient specifically refuses or opts out of testing."

"In areas that use opt-out testing, there are higher acceptance rates," he said. "Therefore, one could hypothesize that there are higher detection rates in women who don't know they're infected. We feel that an opt-out testing strategy should be considered in all jurisdictions."

He and his associates compared the acceptance rates of prenatal HIV testing in a clinic setting that uses a universal opt-out testing strategy with the average acceptance rates in Ontario, which uses an opt-in strategy and has an average testing rate of 50%-60%. All pregnant women had a first intake visit with an obstetric nurse who offers HIV pretest counseling.

The study was performed in two parts. In part one, the charts of 465 pregnant women with intake visits from September through December 2003 were retrospectively reviewed to determine HIV testing rates.

In part two, an ongoing prospective cohort study was launched in February 2004. In this part of the study, the obstetric nurse uses a data sheet to document whether HIV testing was accepted or not, as well as reasons for declining.

In part one of the study, 401 of the 465 women (86%) accepted HIV testing. In 58% of those not tested, there was no reason for refusal documented in the chart. "If a reason was given, the most common was a nonviable pregnancy diagnosed at first visit or a recent negative test prior to the pregnancy." Dr. Yudin said.

In part two, 108 of 131 women studied so far (82%) accepted testing. In 22% of those not tested there was no reason for refusal documented on the data sheet or in the chart.

If a reason was given, the most common was that the patient believed she was not at risk, or that she had a recent negative test prior to the pregnancy.

In both parts of the study, race was a predictor of acceptance of prenatal HIV testing. Hispanic women were five times more likely than were white and Asian women to accept testing, while Asian women were significantly less likely to be tested compared with women from other racial backgrounds.