A quarter of the estimated 950,000 Americans with HIV are unaware that they have it, the CDC says.
SCRIPPS HOWARD NEWS SERVICE
Casting a wider testing net for the AIDS-causing virus HIV to include virtually all Americans would be as worthwhile and cost-effective as common preventive exams including mammograms and colonoscopies, new studies conclude.
"We're convinced based on what we've done that there needs to be more screening. The current approach is clearly inadequate," said Dr. Douglas Owens, an investigator at the VA Palo Alto Medical Center in California and an associate professor of medicine at Stanford University. He is senior author of one of the studies published today in the New England Journal of Medicine.
A second report, by researchers at Yale and Harvard universities, used different data and mathematical models. It concluded that voluntary screening every three to five years is cost-effective for all but very low-risk populations.
"This represents a golden opportunity to jump-start the expansion of HIV testing services in the U.S.," said A. David Paltiel, lead author of the second study and an associate professor at the Yale School of Medicine.
Researchers hope the findings will encourage doctors and clinics to do more testing and insurance companies to pay for the screening.
The Centers for Disease Control and Prevention currently recommends that only such higher-risk populations as intravenous drug users and prostitutes be routinely screened for the AIDS-causing human immunodeficiency virus. Close to one in 100 people in such groups are estimated to be HIV-positive.
But the CDC says that a quarter of the estimated 950,000 Americans with HIV are unaware that they have it. And, the agency says, about 40,000 new infections occur in the United States each year, with about half of them in people unaware they are HIV-positive.
"Past cost-effectiveness studies of HIV screening were conducted before the advent of highly active anti-retroviral therapy, a treatment regimen that has made AIDS a chronic disorder with much longer life expectancies," said Gillian Sanders, an analyst at the Duke Clinical Research Institute and lead author of the study with Owens.
Such new treatments have drastically increased the life expectancy for hundreds of thousands of Americans with the virus. Many researchers believe these therapies have reduced patients' ability to infect others.
But it's important to start the drug regimen early. More than 40 percent of patients don't even learn they have HIV until they start showing symptoms of full-blown AIDS, which prompts them to get tested in the first place.
More extensive testing presumably would get more infected people into treatment earlier and result in less risky interactions with sexual partners. Sanders and Owens calculated, for instance, that one-time routine screening would cut the HIV transmission rate by about 21 percent a year and lengthen the life of an infected person by an average of 1.5 years.
The commonly accepted threshold for cost-effectiveness of medical interventions in this country is $50,000 for each year of "quality-adjusted" life gained. Sanders and Owens found that even in low-risk settings, where as few as one in 2,000 people would be expected to have undiagnosed HIV, the cost of screening would be about $41,000 per added year of higher-quality life.
By comparison, routine screenings for high blood pressure, colon cancer and type-2 diabetes can range overall from $48,000 to $56,000 for each additional year of higher-quality life.
Paltiel's team found similar cost-effectiveness for three- to five-year testing intervals among those who were neither celibate nor in monogamous heterosexual relationships.