Background: Pneumocystis carinii pneumonia (PCP) was the leading cause of hospital admissions in patients with human immunodeficiency virus (HIV) infection before the widespread use of PCP prophylaxis. We studied retrospectively the changes in annual hospital admission patterns after the start of a population-based PCP prophylaxis program in Toronto. The purpose of the study was to identify the cogent diseases requiring hospitalization of HIV patients in the current era of PCP prophylaxis. This information is important for the allocation of health care resources in the future as well as for targeting research in the prevention of specific HIV-related diseases.
Methods: The annual HIV-related hospital admissions before and after the start of the Toronto aerosol pentamidine program (May 1989) were studied. All admission records due to AIDS-defining illnesses or occurring in patients with known HIV status in three major referral centers were reviewed. The two periods for comparison were May 1988 through April 1989 and May 1989 through April 1990. The data obtained were stratified according to the following: (1) cause of the illness prompting hospital admission; (2) PCP admissions; and (3) admissions according to the major organ system involved. These categoric data were compared by nonparametric chi 2 tests.
Results and conclusions: Population-based prophylaxis of PCP with aerosol pentamidine resulted in a significant reduction in the total number of PCP hospital admissions. Infection remains the principal cause of hospital admission in HIV patients after the start of the PCP prophylaxis program. However, there was an increase in the proportion of hospital admissions due to nonrespiratory-related infections. There was also a modest increase in admissions due to neurologic and gastrointestinal diseases. Central nervous system lymphoma and cytomegalovirus retinitis accounted for the majority of the rise in the nervous system. These data suggest there is a changing pattern of the diseases leading to the hospitalization of patients with HIV infection in the era of PCP prophylaxis.