In late September, the federal Centers for Disease Control and Prevention announced new guidelines recommending that all Americans ages 13 to 64 be voluntarily screened for HIV infection. That's a significant change from the previous guidelines, which recommended testing only for high-risk individuals, such as injection drug users or those with multiple sex partners.
The new guidelines were influenced by a study published last year in the New England Journal of Medicine, led by Douglas K. Owens, a CHP/PCOR core faculty member and an investigator at the VA Palo Alto. Owens and his colleagues -- including CHP/PCOR researchers Gillian D. Sanders, Vandana Sundaram, Kristof Neukermans and Laura Lazzeroni -- found that expanding HIV screening would be a cost-effective way to increase life expectancy and decrease the transmission of HIV. Below, Owens discusses the research and the CDC's new screening guidelines.
Q. Why does this new policy matter, and whom will it help?
Owens: The policy is a profound change because it advises that all individuals ages 13 to 64 be screened for HIV. It matters because it will identify people who have HIV but don't know it. These people will benefit because they'll have access to life-prolonging drugs that they otherwise might not have received until very late in the course of HIV disease. The rest of the community will also benefit, through reduced transmission of HIV.
Q. How did your findings contribute to the CDC adopting the new guidelines?
Owens: First, we found that widespread screening provides a substantial health benefit to HIV-positive people who are identified through screening and receive anti-retroviral treatment earlier than they would have otherwise. Early treatment added about a year and a half of life expectancy for these people. Second, we found a substantial potential benefit to the community because of reduced transmission of HIV. Transmission is reduced because many people cut down on risky behaviors (such as having unprotected sex) when they're identified as having HIV, and because anti-retroviral treatment makes a person less infectious. Our key finding was that routine screening is cost-effective even if only 1 in 2,000 people who are screened have HIV. This means HIV screening is cost-effective in a much broader group than recognized previously.
Q. How and why did the CDC revise its previous guidelines? What role did you and your colleagues play in the decision-making?
Owens: CDC officials made this change because they saw mounting evidence that the prior approach to screening -- focusing on those with identifiable risk factors -- simply wasn't working. If you test people based on risk behavior, you miss many people who have HIV. Even among people who had easily identified risk behaviors, many of them weren't being tested. We also know that most people who have HIV are diagnosed very late in the disease, when they can't get the full benefit from anti-retroviral therapy.
Our involvement in the decision-making was to help assess the prevalence of HIV at which routine screening would be recommended. Through several conference calls with CDC officials, we presented our work and explained the issues related to cost-effectiveness and prevalence. Based on those results and the results of a similar study from Yale, the agency went in the direction of lowering the threshold for screening quite substantially -- to 1 in 1,000 from a prior threshold of 1 percent.
Q. Will most physicians follow the new guidelines? What can be done to make sure they do?
Owens: That's the big question. The CDC's previous screening guidelines were not widely adopted. The new recommendations are much easier to adopt, because they don't depend on clinicians determining the prevalence of HIV in their patient population. Still, it will take a lot of follow-up to make sure physicians implement the guidelines. One key obstacle will be getting payers to reimburse for HIV testing. That's a critical issue, which the CDC is well aware of.
Q. Some HIV/AIDS advocates object to the new guidelines because they recommend removing two requirements that some states now have: mandatory signed consent forms and counseling before testing. Does removing these requirements pose a big problem?
Owens: It's important to emphasize that the new guidelines say people should always be informed before testing and should be able to decline. Informed consent and pretest counseling had become significant barriers that were preventing people from being tested who should have been tested. Everyone agrees that no one should be tested without their knowledge, but that doesn't mean you need a separate consent form. Of course, the confidentiality of the test results should continue to be carefully protected. I would point out that some states have laws requiring informed consent, but whether they will now change those laws isn't clear.
