Changing patterns in causes of death in a cohort of injecting drug users, 1980-2001

Background: High mortality among drug users has been widely recognized. This study investigates, in a large family practice of 10000 patients in Edinburgh, Scotland, whether there has been a change in causes of mortality over time. Patients known to have ever injected drugs were recruited into a cohort study from 1980 until 2001. Methods: Death certificates and clinical notes were scrutinized and data relating to demographic features, drug use, and causes of death were recorded. Results: Of 667 patients, there were 153 deaths at follow-up (110 men and 43 women). Average annual mortality rate was 2.3%. Death rate peaked in the early to mid-1990s, reflecting the development of advanced human immunodeficiency virus (HIV) from the early epidemic in 1982-1984 and the onset of the effect of antiviral chemotherapy. Drug deaths and suicide were the same in both sexes but tended to occur in younger subjects. Principal cause of death was overdose in the early years and HIV/AIDS in later years. Toward the close of the study period, hepatitis C emerged as a cause of death. Conclusions: Injecting drug users have a very high risk of mortality. Infectious diseases from nonsterile injecting are the most obvious preventable cause of death. Use of death certificate information alone is inaccurate in analyzing drug-related deaths and greatly underestimates the full impact of the HIV epidemic. This study provides some of the most convincing evidence so far that harm minimization, in its broadest sense, is effective in reducing drug-related mortality.