"We know from other studies that people find out late in the course of the HIV infection-when they're almost to AIDS or already have AIDS," said Owens. "The current approach [to screening] is clearly inadequate."

Owens, along with first author Gillian Sanders, PhD, and their team at the VA, Stanford and St. Michael's Hospital in Toronto, developed a decision model to estimate the health benefits and expenditures of performing voluntary HIV screening programs in health-care settings. They followed a group of patients over their lifetime and looked at the costs and health consequences of screening and counseling, HIV transmission and current treatment guidelines and testing. The researchers used historical data to determine rates of progression for HIV-positive patients not undergoing therapy, and they assumed a 20 percent reduction in risk behaviors for patients whose infection was identified.

The team used its model to determine the benefits of screening due to reduced transmission of HIV and early identification of HIV. The researchers found a 21 percent reduction in annual transmission with the use of a screening strategy, as compared with the absence of screening.

They also found that earlier identification through screening would lengthen life by 1.5 years for a person with HIV infection. In a population in which 1 in 100 persons has unidentified HIV infection (which is consistent with the CDC's recommended prevalence for screening), their model showed that one-time screenings throughout the United States would cost $15,100 per quality-adjusted life year (a common statistical measurement that takes into account quality of life as well as length of survival). And according to their calculations, routine screenings every five years c
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Contact: Michelle Brandt
mbrandt@stanford.edu
650-723-0272
Stanford University Medical Center
9-Feb-2005