Federal guidelines calling for the routine testing of all Americans ages 13 to 64 for the AIDS virus might not be the best way to identify people who are infected but don't know it, a Johns Hopkins scientist said in an article published today.
Dr. David R. Holtgrave, an epidemiologist with the Johns Hopkins Bloomberg School of Public Health, argues that a better way would be "targeted" testing of high-risk patients and populations. That could turn up three times as many infections at the same cost, he estimated.
Holtgrave, writing in an online medical journal, estimated that the health care system would spend $864 million in one year to diagnose almost 57,000 new infections under the government's new policy. This assumes that 1 percent of those tested are infected.
In contrast, he estimated that doctors and public health systems could turn up 188,170 new infections for the same money by concentrating on venues such as drug-treatment facilities, prisons and community health centers in high-risk neighborhoods. These groups have higher risk of HIV than the population as a whole and less access to regular health care.
Targeted testing would also focus on patients, no matter where they live, who are known to have drug habits or engage in sexual activities that put them at risk.
"I don't want to make it seem that I'm anti-testing - the question is whether there are better ways to do this," said Holtgrave, who headed the Centers for Disease Control and Prevention's division of HIV/AIDS prevention in the late 1990s. His article appears in PLoS Medicine.
In issuing the federal guidelines in September, the CDC recognized that universal testing could encroach heavily on a doctor's time. To ease the burden, the agency said doctors could dispense with the practice of counseling patients and obtaining their written consent before testing them for HIV, the virus that causes acquired immune deficiency syndrome. Instead, the onus would be on patients to specifically "opt out" of testing. Doctors would also counsel patients once they tested positive.
But Holtgrave said pre-test counseling is an important way to educate patients about ways to protect themselves and their partners. He estimated that targeted testing and counseling would prevent more than 14,000 new infections a year at a cost of $59,000 per infection prevented, compared with 3,600 infections at a cost of $237,000 each under the federal plan.
"There would be a lot of testing and not much in the way of diagnosis" under the policy of universal testing, he said. "And if we don't do the counseling of people at risk, we're not going to do much in the way of prevention."
Dr. Timothy Mastro, deputy director of the CDC's division of HIV/AIDS prevention, said the federal government has focused most of its energies on reaching high-risk populations. The new policy aims to broaden testing by reducing "missed opportunities" in doctors offices, emergency rooms and elsewhere. "There's a role for targeted testing of people perceived to be at risk," Mastro said. "It's brought us a long way on HIV prevention but not far enough."
There are few places in the nation where testing is more important than Baltimore, which had the second highest rate of new AIDS diagnoses in 2005. Only Miami ranked higher.
"The money we have discretion over, we feel, is much better used reaching out to the highest-risk populations," said Dr. Joshua M. Sharfstein, the city health commissioner. That's why public money is spent on testing vans that go out almost nightly to high-risk neighborhoods and on testing in sexually transmitted disease clinics, he said.
But Sharfstein said he encourages doctors in private settings to test patients too.
Though the CDC issued the policy with some urgency, implementation has been slowed by state laws that require informed consent and counseling of patients before they can be tested for the human immunodeficiency virus. In Maryland, for instance, a statute requires that doctors get a patient's written consent - apart from their agreement for any other blood tests or procedures.
The state's AIDS Administration has convened a panel to study ways to bring state law into agreement with the federal recommendations. Options include streamlining pre-test counseling and consent, eliminating the requirement or keeping it in place, according to AIDS Administration Director Heather Hauck.