Research Brief

Despite the dramatic growth in our knowledge about HIV/AIDS treatment over the past 15 years, several fundamental questions about HIV care still exist: How many persons in the United States receive regular care for HIV infection? What are the characteristics of that population? How much care do HIV-infected individuals use, how much does it cost, and who pays for it?

Policymakers, researchers, and the national community depend upon reliable answers to these questions to help guide their decisions in allocating future resources to HIV treatment and research.

Though much information about HIV care is already available, this data is often limited by the use of non-representative patient samples. Hence, it cannot be used to accurately determine national trends in HIV care. The HIV Cost and Services Utilization Study (HCSUS), however, has generated nationally representative data that can directly answer the questions posed above. This data, collected by an innovative method of probability sampling, also provides a national context for interpreting the results of previous studies based on non-representative samples.

Size and Characteristics of the HIV+ Population

Estimates from the HCSUS indicate that 231,400 adults living in the contiguous United States received regular or ongoing medical care for HIV infection during January and February of 1996. (These estimates exclude those who received care in prisons, the military, or emergency departments only.) Extrapolations from these data suggest that an average of 335,000 individuals, representing approximately 43 percent of HIV-infected adults, received care during any typical six-month period in 1996. These figures are based in part upon data from the Centers for Disease Control, which estimates that there is a total population of 650,000 to 900,000 HIV-infected Americans.

Almost 90 percent of those represented by the HCSUS were less than 50 years old. Slightly more than three-quarters were men; about half were non-Hispanic whites, while one-third were African-Americans. Overall, their incomes tended to be quite low: 46 percent had an annual household income of less than $10,000, a level that places them in the bottom quintile of the general population.

Of the 231,400 HIV-infected adults directly represented by the HCSUS, an unexpectedly high 59 percent met the CDC case definition for AIDS. This finding contrasts with natural history studies, which indicate that only about 35 percent of those with HIV infection meet the AIDS criteria. Thus, the HCSUS data suggests that many of those in the early stages of the disease are not receiving regular medical care.

Utilization and Costs of Medical Services

Public programs support much of the HIV+ population . . .

. . . and their beneficiaries are in more advanced stages of disease

In the six months prior to their baseline interview, members of the HCSUS population averaged 1.4 outpatient visits per person per month; one-third visited an emergency department at least once and 20 percent were hospitalized. Eighty-five percent used at least one HIV medication. As the study progressed, new HIV drugs (protease inhibitors and non-nucleoside reverse transcriptase inhibitors) became widely available. Although use of these drugs increased substantially during 1996, more than 40 percent of patients with appropriate indications had not received a trial of either type of drug by the end of the year.

For adults receiving regular care for their HIV infection (at least one visit every six months), direct medical expenditures on HIV care were estimated to be $20,000 per patient per year, or approximately $6.7 billion for all HIV care in 1996. Hospital care (46 percent) and pharmaceuticals (40 percent) accounted for the bulk of the expenditures. Outpatient care (12 percent) and emergency department care (2 percent) comprised the remainder. Though these sums are significant, they are not unreasonable in context of the morbidity and mortality associated with HIV/AIDS: HIV accounts for 8 percent of the total potential years of life lost in the United States, but HIV care constitutes less than 1 percent of direct health care expenditures.

Underwriting the Costs of HIV Care

Tragically, less than half of all HIV-infected adults in America today receive regular medical care. In part, this situation stems from difficulties in financing care. Only one-third of all HIV-infected Americans possesses private insurance, while fully one-fifth is uninsured. Public insurance—Medicaid and Medicare—covers the remaining half. Medicaid and Medicare, in turn, bear the brunt of the cost of HIV care, due to the large proportion of HIV-infected individuals they cover and the advanced stage of disease associated with their beneficiaries. (See accompanying graphs for further details.) As the HIV/AIDS pandemic continues, the proportion of individuals who lack private insurance and eventually become dependent upon public sector programs is likely to increase. Thus, one of the most significant health care policy challenges of the next decade will be to find ways to expand access to HIV care, while simultaneously implementing new and fiscally sustainable approaches to underwriting the cost of that care.

This report is part of the RAND Corporation research brief series. RAND research briefs present policy-oriented summaries of individual published, peer-reviewed documents or of a body of published work.

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