Background: The HIV/AIDS epidemics has contributed to an excess of morbidity and mortality in injecting drug users. The main goal of this study is to estimate incidence and factors associated with mortality from different causes among intravenous drug users.
Subjects and methods: Prospective study of patients admitted to a detoxification unit between 1987 and 1990. At baseline they underwent interviews (drug injecting patterns) and venipuncture for HIV and other parameters including T-cell subsets. Viral status was determined for those who returned at least once. Cumulative incidence, overall and cause-specific mortality rates were calculated according to gender, HIV at admission and length of injecting drugs.
Results: 420 patients (334 men, 86 women), 69.6% HIV+, were admitted to treatment; the mean age of participants was 26 years and the mean duration of injecting drugs was 73 months. Three hundred and eighty seven patients were followed-up (92% of the initial cohort) for 2,029 persons-years and 101 deaths occurred. The overall mortality rate was 50/1000 persons-year (52/1000 for men and 40/1000 for women). The relative risk (RR) for death among women compared with men was 1.3 (95% CI = 0.8-2.2). The mortality rates for HIV+ was 60/1000 persons-year and 29/1000 persons-year for the seronegatives (RR: 2.1; 95% CI = 1.2-3.4). The HIV+ patients with CD4/microliter < or = 500 showed a threefold increase in mortality rates compared to HIV+ patients without immunosuppression (CI = 1.7-5.3). The cause-specific mortality rates were 27/1000 persons-year for HIV/AIDS, 15/1000 persons-year for drug overdose, 3/1000 persons-year for violence/trauma and 1/1000 persons-year for non-AIDS conditions.
Conclusions: In this hospital cohort, HIV/AIDS and overdose have had a marked effect on mortality among intravenous drug users. Detoxification units may provide clinical services and extensive use of antiretroviral treatment for HIV infected drug users as a strategy to reduce the risk of death from AIDS.