HIV/AIDS Research

Use of medicines other than ZDV to treat HIV infection has increased greatly over the past 5 years

Patients infected with the human immunodeficiency virus (HIV) that causes acquired immunodeficiency syndrome (AIDS) are no longer relying only on zidovudine (ZDV), the first antiretroviral licensed to treat AIDS (1987). Patients and their physicians are increasingly choosing treatments that combine ZDV with other retrovirals licensed since 1990: didanosine (ddI), zalcitabine (ddC), and stavudine (d4T); or they are using these newer antiretrovirals alone.

Researchers from The John Hopkins School of Public Health studied use of antiretroviral therapy in 1,129 HIV-infected homosexual and bisexual men in four cities who participated in a Multicenter AIDS Cohort Study (MACS). From 1990 to 1994, the proportion of men using ZDV monotherapy decreased from 27 percent to 17 percent (among men without an AIDS diagnosis) and from 60 percent to 17 percent (among men with an AIDS diagnosis). At the same time, the proportion of men using combination therapy increased from zero to 11 percent (without AIDS) and from 2 percent to 21 percent (with AIDS), and the proportion switching to a different monotherapy increased from zero to 8 percent (without AIDS) and from 8 percent to 26 percent (with AIDS).

Men without AIDS usually switched to combination therapy in response to declining CD4 lymphocyte counts or increased HIV symptoms (indications of drug failure). Men with AIDS usually switched to an alternative monotherapy. These choices reflect the current tendency of clinicians to use combination therapy for intermediate-stage HIV disease for its presumably stronger impact on sustaining CD4 count compared with monotherapy.

This research was supported by an intraagency agreement between the Agency for Health Care Policy and Research and the National Institute of Allergy and Infections Diseases (NIAID). More details are in "Factors associated with changes in the use of antiretroviral therapy by a cohort of homosexual men infected with the human immunodeficiency virus type I," by Lawrence P. Park, M.S.E., Neil M.H. Graham, M.D., Lisa P. Jacobson, Sc.D., and others, in Clinical Infectious Diseases 21, pp. 930-937, 1995.

Disadvantaged groups lag behind other patients in receipt of new HIV treatments

Innovative medical treatments often take longer to reach disadvantaged social groups. This was the case when zidovudine (ZDV), formerly known as AZT (azidothymidine), was first approved in 1987 to treat infection with the human immunodeficiency virus (HIV). HIV-infected blacks, women, and intravenous drug users (IDUs) who participated in New Jersey's Medicaid waiver program for HIV-infected persons (which paid for ZDV) were less likely to receive ZDV treatment than other program participants for the first 2 years after introduction of the treatment. However, by 1990 these groups received ZDV treatment and continued on the treatment at about the same rate as other Medicaid waiver patients.

Researchers in New Jersey, who were supported in part by the Agency for Health Care Policy and Research (HS06339), studied the use of ZDV among two groups of adults enrolled in New Jerseys Medicaid waiver program, those enrolling in 1987 and 1988 and those enrolling in 1989 and 1990. In the earlier group, only 45 percent of blacks vs. 63 percent of others had any use of ZDV, and ZDV use by women and IDUs was less likely to be sustained over time. For those taking ZDV, the proportion of time on the treatment was 41 percent for IDUs vs. 51 percent for others and 34 percent for women vs. 48 percent for men.

By 1989-1990, when ZDV use had become a more broadly applied standard of care for HIV-infected persons, there were no significant differences by race, sex, or risk group (for example, IDU or homosexual) in receipt of ZDV (overall range of 65-71 percent), and differences in treatment persistence disappeared. The researchers conclude that differences in source of care (hospital clinic vs. private physician) probably contribute to socioeconomic differences in treatments received, especially for treatments that are new or require careful medical monitoring for success.

Details are in "The diffusion of innovation in AIDS treatment: Zidovudine use in two New Jersey cohorts," by Stephen Crystal, Ph.D., Usha Sambamoorthi, Ph.D., and Cheryl Merzel, Dr.P.H., in Health Services Research 30(4), pp. 593-614, 1995.

Voluntary HIV screening found to be cost-effective at some hospitals

Voluntary human immunodeficiency virus (HIV) screening of patients at hospitals where 1 percent of patients are typically infected with the virus is nearly as cost-effective as hypertension screening, according to a study supported by the Agency for Health Care Policy and Research (HS07273).

Routine voluntary HIV screening of inpatients and outpatients aged 15 to 54 years in high-prevalence hospitals has been recommended by the Centers for Disease Control and Prevention (CDC) but has not been widely adopted because of cost concerns. The recent study shows that this HIV screening program would identify about 110,000 undetected cases of HIV infection at a cost of $47,200 per year of life saved, which compares favorably with the $12,200 to $42,600 per year of life saved with hypertension screening.

The HIV screening program becomes even more cost-effective if individuals identified as HIV-infected respond to the test results by seeking appropriate medical care for their condition and by reducing high-risk sexual and other behaviors that may transmit HIV infection to others, notes lead investigator Douglas K. Owens, M.D., M.Sc. Dr. Owens and colleagues at the Veterans Affairs Palo Alto Health Care System and Stanford University Medical Center had previously found that a one-time national screening program to identify HIV-infected surgeons would be very costly, averaging $458,000 per year of life saved.

In this latest study, the researchers used a decision model to estimate the cost-effectiveness of the CDC-recommended screening program in acute care hospitals and associated clinics. Assuming that half of individuals identified as HIV-positive either declined to be treated or did not have access to medical care, the cost-effectiveness of the program would decline substantially from $47,200 per year of life saved to $59,600 per year of life saved. Assuming that a modest 15 percent of infected persons would change their behavior to reduce the risk of HIV transmission, the programs cost would decrease from $47,200 to $36,600 per year of life saved, an almost 25 percent improvement in cost-effectiveness. However, the researchers noted an important caveat: the effect of screening and early identification on quality of life is not well understood. If early identification decreases quality of life, the cost-effectiveness of a screening program declines from $47,200 per year of life saved to $92,400 per quality-adjusted year of life saved.

Details are in "Cost-effectiveness of HIV screening in acute-care settings," by Dr. Owens, Robert F. Nease, Jr., Ph.D., and Ryan A. Harris, M.S., in the February 26, 1996 Archives of Internal Medicine, pp. 394-404. For information about the earlier study, see "Screening surgeons for HIV infection: A cost-effectiveness analysis," by Dr. Owens, Ryan A. Harris, M.S., Patricia McJ. Scott, A.B., and Robert F. Nease, Jr., Ph.D., in the May 1995 Annals of Internal Medicine 122(9), pp. 641-652.

Rural AIDS cases have risen dramatically among some groups

Cases of acquired immunodeficiency syndrome (AIDS) among rural residents have risen dramatically in the past 5 years, especially among women, blacks, and adolescents. From 1991 to 1992 alone, rural AIDS cases increased at three times the rate of urban cases (9.4 vs. 3.1 percent). Until recently, many of these new cases were urban AIDS patients returning home in the last stages of their illnesses. However, this group (made up mostly of homosexuals) is being replaced by locally infected persons who are more apt to be female and heterosexual, according to a study supported by the Agency for Health Care Policy and Research (282-93-0040).

Unfortunately, rural health care providers have limited resources and very limited experience in treating human immunodeficiency virus (HIV) infection and AIDS, explains Robin P. Graham, Ph.D., M.P.H., of the State University of New York at Buffalo, the study's lead investigator. An extensive review of the research literature by Dr. Graham and colleagues revealed that rural county AIDS cases increased more than five-fold between 1985 and 1991 in contrast to less than a two-fold increase in urban counties. Nearly one-third (30 percent) of rural HIV/AIDS cases were concentrated in the South Atlantic States.

Even after controlling for intravenous drug use, infection rates for rural black women were 20 times higher than for rural white women. Also, rural American Indian and Native Alaskan females had HIV infection rates comparable to their urban counterparts. In contrast to urban adolescents, rural female adolescents had infection rates nearly equal to those of rural males. Finally, rural groups at greatest risk for AIDS continue to be those least able to pay for care.

Details are in "HIV/AIDS in the rural United States: Epidemiology and health services delivery," Dr. Graham, Maureen L. Forrester, M.S., Jere A. Wysong, Ph.D., and others, in the December 1995 Medical Care Research and Review 52(4), pp. 435-452.

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