Mortality trends in a cohort of opiate addicts, Catalonia, Spain

Opiate addiction affects young adults whose life expectancy is reduced as a consequence of their habit. In the midst of the AIDS epidemic, the present study objective was to analyse recent overall and cause-specific mortality trends among opiate addicts in Catalonia (Spain).

Mortality was assessed retrospectively in an opiate addict cohort assembled from admissions to hospital emergency wards and drug treatment centres during the period 1985-1991. The cohort included 12 711 opiate addicts (12 045 men and 3666 women) aged 15-44 years. Overall and cause-specific mortality trends were analysed using age as the time scale and Cox regression with staggered entry determined by the age at entry in the study. Annual trends were adjusted by sex and source of entry, and were stratified by length of opiate use.

Mortality rates increased throughout the entire period from 13.8 to 34.8 deaths per 1000 person-years, with a statistically significant increase in 1987-1988 and 1988-1989. In a model including age, gender, source of entry and length of drug use, risk increased significantly in men and for longer length of use, but not with age and for source of entry into the study cohort. The causes of death associated with high mortality rates were AIDS and the causes directly related to addiction.

A threefold increase in mortality rates was observed during the period, mainly accounted for by AIDS and direct addiction-related causes. Length of opiate use was an important determinant of mortality.