Private medical insurance among Philadelphia residents diagnosed with AIDS.

We used medical insurance information gathered on each Philadelphia resident with AIDS to examine time trends in private medical insurance at the time of diagnosis. The proportion of AIDS patients with private medical insurance decreased from 51.9% in July-December 1988 to 28.6% in July-December 1991. During the same time period, an increasing proportion of people diagnosed with AIDS were female, poor, members of minority groups, or abusers of injection drugs. A discrete multivariate model showed that the (point) prevalence of private medical insurance at AIDS diagnosis decreased significantly with time, even after adjustment for changes with time in the age, gender, race, estimated income, history of injection drug use, and history of homosexual contact of those who were affected with AIDS. Thus the decreasing prevalence of private medical insurance among people newly diagnosed with AIDS does not simply reflect changes in the demographic and behavioral characteristics of the people affected.