Increased frequency of overdose deaths among HIV-infected injection drug users

The increased frequency of AIDS-related deaths among HIV infected drug users is well established; but the suggested association of HIV infection and overdose deaths remains controversial. To assess cause-specific mortality by HIV serostatus, a cohort of injection drug users assembled between February 1988 and March 1989 using community recruitment techniques, underwent interviews and HIV serology at baseline and semiannually thereafter. Underlying cause of death was determined through December 1995 by vital records search. Cause-specific mortality was compared by HIV serostatus using person-time techniques and Poisson regression. Among 2203 participants, median age was 34 years old, 92% were black, 80% were male, 91% had injected within the year prior to baseline, and 30% were HIV seropositive at baseline. The overall mortality rate was 416 deaths during 14,600 person years of follow-up (1.7/100 person years). Mortality was higher in HIV seropositives than in uninfected persons (rate ratio [RR]=3.8), even after excluding deaths due to or subsequent to AIDS (RR=1.6). HIV seropositives were more likely than uninfected persons to die from sepsis/endocarditis (RR=2.8) and drug overdose (RR=1.9) prior to the onset of AIDS, even after adjusting for other correlates of death. 90% of those with overdose deaths reported injection within prior year. Although the excess risk of death from sepsis/endocarditis with HIV infection is consistent with earlier studies of HIV-related morbidities, the association between overdose deaths with HIV infection merits closer scrutiny.