A new cost-effectiveness analysis has led researchers from Duke University Medical Center and the Veterans Affairs (VA) Palo Alto Health Care System to recommend that routine voluntary screening for HIV, the virus that causes acquired immune deficiency syndrome (AIDS), should be expanded well beyond current guidelines to include health care settings where the incidence of the virus would be expected to be low.
These include such settings as outpatient clinics, urgent care clinics or emergency rooms in areas that have in the past been deemed low-risk for HIV. The researchers recommended expanded testing because of the success over the past decade of highly active antiretroviral therapy (HAART) in prolonging the quantity and quality of lives of patients infected with AIDS, as well as decreasing the rate at which those infected with the virus can transmit the disease to others.
HAART therapy involves using multiple drugs, all of which block replication of HIV genes. For most patients, these drugs combinations have reduced the viral load in the blood to virtually undetectable levels. Not only has this therapy increased the life expectancies of infected patients, but researchers believe that HAART also reduces their infectivity.
The results of the cost-effectiveness analysis were published Feb. 10, 2005, in the New England Journal of Medicine.
"While the Centers for Disease Control and Prevention's guidelines are that routine screenings are effective in settings where there is a one percent or above prevalence of disease, our analysis showed that such screening at much lower prevalence levels would provide important benefits. In addition we found this screening would be cost-effective and in-line with other commonly accepted screening programs," said lead author Gillian Sanders, Ph.D., a medical decision analyst at the Duke Clinical Research Institute.
"Past cost-effectiveness studies of HIV screening were conducted before the advent of HAART, a treatment regiment that has made AIDS a chronic disorder with much longer life expectancies," Sanders said. "Our study's results should provide the medical community, health care administrators and policy-makers with the data they need to expand screening."
Sanders' paper is being published alongside a study from researchers at Yale and Harvard with similar results. "These two independent studies provide great external validation for each other – emphasizing the robustness of our findings and the value of expanded HIV screening," she said.
Sanders led the study with colleagues from the Palo Alto (Calif) VA Health Care System, Stanford University, and St. Michael's Hospital, Toronto. The study was funded by the Department of Veterans Affairs Research and Development Service, the Ontario HIV Treatment Network and the National Institute of Drug Abuse.
For their analysis, the team used a model that accounts for a wide variety of variables, including patient characteristics, the natural history of the disease, the timing of testing and treatments, immunological status, outcomes, medical costs, and quality of life parameters. The data used for the model were drawn from the latest clinical trial results and studies published in the scientific literature.
The model targeted patients who were unaware of their HIV status when they entered the health care system, whether at a hospital, clinic, routine medical or emergency room visit. The model then calculated the incremental costs and benefits across the lifetime of typical patients. As a part of their analysis, the researchers assessed the cost-effectiveness with and without considering the benefits to the sexual partners of the patients.
In the U.S., the commonly accepted threshold for the cost-effectiveness of medical therapies is $50,000 per quality-adjusted life-year gained. A cost-effectiveness ratio below $50,000 is usually considered cost-effective and the treatment would be considered good value for the money. In these analyses, researchers not only include the potential medication, hospitalization and other medical costs, but also take into account quality-of-life benefits patients receive for their added life expectancies.