STANFORD, Calif. -- HIV/AIDS patients with public insurance (such as Medicaid) have much lower death rates than those with no insurance, thanks mainly to coverage of life-saving yet expensive anti-retroviral drugs, according to a study by researchers at Stanford University's Center for Health Policy/Center for Primary Care and Outcomes Research and the RAND Corp.

The findings, which take into account the severity of patients' illness, indicate that expanding public insurance coverage for HIV/AIDS patients could reduce HIV/AIDS-related deaths among the uninsured by up to 66 percent.

While documenting the life-saving impact of public insurance on HIV/AIDS patients, the study, published in the latest issue of the Journal of Health Economics, also found that public insurance is about 20 percent less effective than private insurance coverage in preventing HIV/AIDS deaths. The finding, study authors say, is likely due to the stringent eligibility rules and drug-coverage provisions of many states' Medicaid programs, which limit access to the class of lifesaving drugs known as highly active anti-retroviral therapy, or HAART.

The Stanford/RAND study is the first to examine the impact of public insurance, private insurance and no insurance on mortality rates for HIV/AIDS patients. It is also the first study to examine the mortality impact of state Medicaid programs with strict eligibility rules and drug-coverage provisions for HIV/AIDS, versus those with less restrictive rules.

"Expanding insurance for HIV patients clearly can save lives, and these expansions will save the most lives if they ease the restrictions that limit access to HAART," said study author Jay Bhattacharya, MD, PhD, assistant professor of medicine at Stanford University and a researcher at the university's Center for Health Policy/Center for Primary Care and Outcomes Research.

In many states' Medicaid programs, the study notes, eligibility restrictions effectively force AIDS patients to get very sick or very poor, or both, before they quality for coverage. Once covered by Medicaid, furthermore, many HIV/AIDS patients still don't have access to HAART, because they're not considered sick enough under the program's rules, or they've reached a limit on the number of prescriptions they can fill each month.

Previous research by the Stanford/RAND group has found that state Medicaid programs could save money by covering HAART for more patients, as the drugs often keep patients well enough to avoid hospitalizations and other expensive care. Medicaid -- which is administered jointly by the federal and state governments and has different rules in different states -- is the most widely available public insurance program for HIV/AIDS patients, along with other state-run programs such as AIDS Drugs Assistance Programs.

Bhattacharya's research team used data from the HIV Costs and Services Utilization Study, a large national survey of HIV/AIDS patients conducted for the federal government by the Santa Monica, Calif.-based RAND Corp. Through in-person interviews, the survey gathered information on a random sample of nearly 2,500 patients treated for HIV/AIDS between 1996 and 1999.

In analyzing the data, the researchers adjusted for the severity of the patients' illness -- an important step, as HIV/AIDS patients covered by public insurance tend to be much sicker than uninsured or privately insured patients, because in many states they do not qualify for Medicaid until they have entered the advanced stages of the disease.

As a result, uninsured HIV/AIDS patients often face a cruel choice: spend most of their savings on AIDS drugs until they are poor enough to qualify for Medicaid (HAART costs an average of $13,000 per year), or forego the drugs and wait until they are sick enough to quality for the program under medical eligibility rules.

When they adjusted for the severity of patients' illness, the researchers found that the death rate for publicly insured AIDS patients is 66 percent lower than for the uninsured. Put another way, expanding public-insurance coverage for HIV/AIDS patients could increase by 66 percent the number of patients who survive in a given year.

The researchers also reported that death rates for publicly insured HIV/AIDS patients were significantly lower in states whose Medicaid programs had less-restrictive eligibility rules and more generous drug coverage, compared with states that imposed greater restrictions.

Bhattacharya said he and his research team were "rather surprised at what a strong positive effect public insurance had on this population." The findings, he said, point to several policy changes that could extend the lives of HIV/AIDS patients -- such as expanding states' AIDS Drugs Assistance Programs and extending Medicaid coverage to all HIV-positive patients.

The study was funded by the federal Agency for Healthcare Research and Quality. Co-investigators were Dana Goldman and Neeraj Sood of the RAND Corp.

The Center for Health Policy and the Center for Primary Care and Outcomes Research are sister centers at Stanford University that conduct innovative, multidisciplinary research on critical issues of health policy and health-care delivery. Operating under the Stanford Institute for International Studies and the Stanford School of Medicine, respectively, the centers are dedicated to providing public- and private-sector decision-makers with reliable information to guide health policy and clinical practice. For more information, go to http://healthpolicy.stanford.edu.