5 questions: Douglas Owens on HIV screening
The Centers for Disease Control and Prevention recently announced new voluntary guidelines recommending that all Americans ages 13 to 64 be screened for HIV. That's a significant change from the previous guidelines, which recommended testing only for high-risk individuals, such as those with multiple sex partners. The new guidelines were influenced by research published last year, led by Douglas Owens, professor of medicine and an investigator at the VA Palo Alto Health Care System. Owens' team found that expanding HIV screening would be a cost-effective way to increase life expectancy and decrease the transmission of HIV. Owens spoke with Medical Center Report about this work and the new screening guidelines.
1. Why does this new policy matter?
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. They 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.
2. 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 benefit to the community because of reduced transmission of HIV. Transmission is reduced because many people cut down on risky behaviors when they're identified as having HIV, and because anti-retroviral treatment makes a person less infectious. Our key finding was that screening is cost-effective even if only one in 2,000 people who are screened has HIV. This means HIV screening is cost-effective in a much broader group than was recognized previously.
3. Did you and your colleagues play a role in the decision-making?
Owens: CDC officials made this change because they saw mounting evidence that the prior approach to screening wasn't working. If you test people based on risk behavior, you miss many people who have HIV. We also know that most people who have HIV are diagnosed very late in the disease, when they can't fully 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, the agency went in the direction of lowering the threshold for screening quite dramatically—to one in 1,000 from a prior threshold of one in 100.
4. Will most physicians follow the new guidelines?
Owens: That's the big question. The 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 aware of.
5. Some HIV/AIDS advocates object to the new guidelines because they recommend removing two requirements that some states have: mandatory, signed consent forms and counseling before testing. Is that 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 substantial barriers that were preventing people from being tested. Certainly 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.