Risk of developing AIDS in HIV-infected cohorts of hemophilic and homosexual men.

The latency period and/or incidence of the acquired immunodeficiency syndrome (AIDS) may differ in persons infected with the human immunodeficiency virus by different routes or having different "cofactors." We compared 79 hemophilic men in Pennsylvania and 117 homosexual and bisexual men in California, all having known dates of infection and long postinfection observation periods, to examine these hypotheses. By 1987, twenty-one percent of the hemophilic and 27% of the homosexual men had developed AIDS. However, seroconversion patterns differed for the two groups, and when this was taken into account, the conditional odds ratio for AIDS was 1.20. Kaplan-Meier survival analysis showed no significant difference in the cumulative proportion with AIDS, from time of infection. These results are limited by the small size and geographically localized nature of our study populations, but they suggest that currently the relative length of human immunodeficiency virus infection is of primary importance in comparing disease outcome for different populations.