Temporal trends in the progression of human immunodeficiency virus disease in a cohort of drug users

We evaluated changes over time in rates of progression to AIDS, mortality, and distribution of AIDS-defining illnesses in 524 human immunodeficiency virus (HIV)-seropositive injection drug users enrolled between 1986 and 1995 in a prospective study of HIV infection in the Bronx, NY. At enrollment, participants attended a hospital-affiliated methadone maintenance program with on-site primary care. Using the 1993 clinical definition of AIDS, we found that the hazard ratio (HR) of progression to AIDS declined for enrollees over time in comparison with the referent group of persons enrolled in 1986-1987. For program enrollees in 1988-1989, the HR was 1.0 [95% confidence interval (CI) = 0.6-1.6]; for enrollees in 1990- 1991, the HR was 0.3 (95% CI = 0.1-0.9); for enrollees in 1992-1993, the HR was 0.5 (95% CI = 0.3-0.9); and for enrollees in 1994-1995, the HR was 0.2 (95% CI = 0.1-0.7), after controlling on initial CD4⁺ cell counts and age. Nevertheless, the greater AIDS-free time of later study entrants was not associated with reduced mortality. The study provides evidence that drug users with access to primary care likely benefited from improved management of HIV disease in prolonging AIDS-free time but, through 1996, did not experience greater survival.