Has mortality in drug addicts increased? A comparison between two hospitalized cohorts in Stockholm

Substance abusers are known to have a high mortality, but the mortality rate and cause of death pattern has varied between studies and over time. The aim of the study was to compare the mortality in two cohorts of hospitalized drug addicts in Stockholm County identified in 1971-1972 and 1980-1981, respectively.

Two cohorts consisting of all patients admitted for drug dependence in 1971-1972 and in 1980-1981, were selected from Stockholm County inpatient register. Both cohorts were followed for a mean time of 10 years with regard to mortality. Standardized mortality ratios (SMR) and Cox hazard regression models were computed.

Mortality in the two cohorts did not differ significantly. However, differences were found between subgroups. Thus for addicts using opiates, the death rate was twice as high as that of central stimulant users. For those addicts mixing drugs, the death rate was 48% higher compared to the central stimulant users. Males and people over 34 years of age had a significantly higher death rate than females and younger people. Mortality in drug addicts, especially opiate addicts, remained very high, though stable, over the study period. Patients in the 1980-1981 cohort were at risk of HIV/ AIDS but this had not increased the excess mortality.

There was no significant difference in overall mortality between the two cohorts and the causes of death patterns seemed quite stable over time.