Studying the cost of HIV-related illnesses: reflections on the moving target.

Although medical care costs of the HIV epidemic by 1991 may reach $6 billion, or 1.2 percent of all estimated personal health care expenditures in the United States, costs per patient of treating AIDS appear to be declining. Calculating the epidemic's costs is difficult, however, in that data are lacking on health care expenditures for HIV-infected persons other than those with AIDS, intravenous drug users, women, and children. Shifts in demographic segments affected, changes in medical treatments, and diffusion beyond initial urban centers will alter the economics of AIDS. Prospective studies at both national and local levels are needed to gauge the epidemic's costs and demands on health services.