Mortality Among Drug Users in the AIDS Era

Background: Infection with human immunodeficiency virus type 1 (HIV-1) causes progressive immune deficiency, the acquired immunodeficiency syndrome (AIDS), and death. Mortality, however, particularly with causes other than AIDS, deserves further study. A retrospective cohort study among drug users in Italy was performed to estimated absolute and proportional mortality rates due to AIDS and other causes, with or without HIV-1 infection.

Methods: All subjects who enrolled between January 1980 and July 1990 in the drug treatment programme in the Province of Bologna, Italy, were included in the cohort. Each subject was categorized for HIV-1 antibody status (positive, negative, untested), vital status (in 1990 by national surveillance), and causes of death (by death certificate). Data were analysed with actuarial and time-dependent covariate methods.

Results: There were 332 deaths among 4962 drug users who were followed for 21,130 person-years. This mortality rate (1.57 per 100 person-years) was increased 18-fold compared to the general population. Actuarial 10-year mortality estimates were 28.2% for the 2040 HIV-1 positive subjects, 12.1% for the 1859 HIV-1 untested subjects, and 2.5% for the 1063 HIV-1 negative subjects. AIDS contributed to 150 deaths, followed by drug overdose (64 deaths) and trauma (39 deaths). Compared to others in the cohort, mortality with AIDS and non-AIDS causes was reduced for HIV-1 negative subjects. In contrast, mortality for HIV-1 positive subjects was increased with AIDS, trauma, overdose, various bacterial infections, hepatitis, and cirrhosis.

Conclusions: Mortality with HIV-1 infection was associated not only with opportunistic infections and malignancies but also with competing causes of death, particularly hepatic disease. Further investigation is needed to clarify whether alcohol, analgesics, hepatitis viruses, or other agents have enhanced hepatotoxicity for HIV-1 infected patients.