WEDNESDAY, Jan. 20, 2016 (HealthDay News) -- Telling people they'll be screened for HIV unless they decline to be tested -- an approach known as "opt-out" testing -- could significantly increase the number of patients who agree to be tested, new research suggests.
Other approaches to HIV screening, such as leaving it up to patients to specifically ask to be tested, could have the opposite effect, researchers said.
"Our study provides evidence that small changes in wording can significantly affect patients' behavior and thus our understanding of their preferences and is crucial to providing patient centered care," wrote study leader Juan Carlos Montoy, from the University of California, San Francisco, and colleagues.
The study, which involved 4,800 patients seen in the emergency room, is the first randomized controlled trial to evaluate consent for HIV testing. None of the patients involved had ever tested positive for the virus.
The researchers divided the patients into three groups based on different approaches to offering HIV testing. The first group received an "opt-in" approach, which let them know that testing was available but they had to specifically request the test. The second group received an "active choice" approach and were directly asked if they wanted to be tested for the virus. The third group received the "opt-out" approach. These people were tested for HIV unless they specifically asked not to be screened.
The study found 38 percent of the patients in the "opt-in" group agreed to be tested for HIV. Meanwhile, 51 percent of those in the "active choice" group and 66 percent in the "opt-out" group accepted the HIV test, the study authors said.
The study results were published Jan. 19 in the BMJ.
Although patients may prefer to be asked directly if they want to be tested, the study authors concluded that the "opt-out" approach could increase the number of patients actually tested for the virus. They noted this is particularly true for those at intermediate and high-risk for HIV infection. These patients, the study showed, were more likely to accept testing than those in low-risk groups. The effects of the "active choice" approach to testing however, didn't vary by level of risk behavior.
The researchers concluded that more research is needed to assess the effects of the various approaches to HIV screening.
Around the world, 37 million people are infected with HIV, the virus that causes AIDS. About 46 percent of those infected with the virus remain undiagnosed. HIV testing is critical to controlling the epidemic. "Opt-out" testing has been endorsed in the United States. Europe is also moving toward this approach to testing, the researchers said.
The U.S. Centers for Disease Control and Prevention provides more information on HIV testing.