Drug-related mortality and its impact on adult mortality in eight European countries

Objective: To estimate the mortality rates from drug-related deaths and other causes among problem drug users and population attributable risk of death due to opiate use in eight study sites in Europe. Methods: Opiate users were recruited from drug treatment centres during the period 1990-1998 and deaths followed up through national or local mortality registries. Gender-specific overall mortality rate, proportion of deaths by cause (drug-related, HIV, other), standardized mortality ratios (SMRs), and the attributable risk fraction (ARF) were estimated. Results: Crude mortality rates varied from 1 per 100 person-years in the Dublin and London cohorts to 3.8 per 100 person-years in Barcelona. The highest drug-related mortality rate was 10 per 1000 person-years in Barcelona; the rates were similar to 7 per 1000 person-years in Denmark, London, Rome, and Vienna, and < 3.5 per 1000 person-years for the others cohorts. The mortality rate for AIDS was < 2 per 1000 person-years in all the cohorts except Lisbon, Rome, and Barcelona, for which it was similar to 6 per 1000 person-years. The highest SMR among males was 21.1 in Barcelona, and among females the highest SMRs were 53.7 and 37.7 in Barcelona and Rome, respectively. In Denmark the ARF was 5%, whereas it was > 10% in all other study sites and 24% in Barcelona. Conclusion: Cohort mortality studies, especially in combination with estimates of prevalence, provide useful insights into the impact of opiate use on mortality across European countries and emphasize how preventing overall and drug-related deaths among opiate users can significantly improve the health of the population.