Patterns and 14-year trends in mortality among illicit drug users in Finland: the HUUTI study

BACKGROUND

Although mortality is a known complication of illicit drug use, robust epidemiological studies on drug-related mortality in Finland are scarce. We examined all deaths, specific causes of death, and trends in mortality among a large number of illicit drug users in Finland during a 14-year period.

METHODS

Details of 4817 clients who sought treatment for drug use at Helsinki Deaconess Institute between 1997 and 2008 were linked to national cause of death register to identify all deaths and causes of death. Standardised mortality ratios (SMRs) were calculated to compare all-cause deaths in our study cohort with those in the general population. Trends in mortality rates were assessed using Poisson (log-linear) regression.

RESULTS

A total of 496 deaths occurred during 41,567.5 person-years with crude mortality rate of 1193.2 per 100,000 person-years. Mean follow-up was 8.6 years and the mean age at death was 33.8 years. Most deaths (84.1%) occurred among male clients, 189 deaths occurred in the 25-34 age-group and all-cause SMR was 8.9 [95% confidence interval (CI)=8.1-9.7]. Two-thirds (64.9%) were deaths from external causes and 35.1% from disease-related causes. The four leading causes of death were accidental poisoning/overdose (n=165), suicide (n=108), mental and behavioural disorders (n=49) and circulatory system diseases (n=45). Younger clients died from acute effects of drug use while older clients died more from chronic health conditions. A decline in annual rates was noted for all-cause mortality (P=0.01), deaths from mental and behavioural disorders (P<0.001) and suicides (P<0.001).

CONCLUSION

The four leading causes of death among illicit drug users are preventable. Overdose management training, drug education and other preventive measures could help reduce mortality.