Long-term mortality and causes of death among hospitalized Swedish drug users

Abstract

Aim: To study long-term mortality and causes of death in a cohort of drug users in relation to main type of drug use and HIV-status.

Methods: A total of 1640 hospitalized drug users in Stockholm was followed up from 1985 to the end of 2007. The mortality was compared with the general Swedish population and hazard ratios (HR) for the main risk indicators were calculated. The causes of death were studied, using information from death certificates.

Results: 630 persons died during the observation period. The Standard Mortality Ratio (SMR) was 16.1 (males 13.8, females 18.5). The crude mortality rate was 2.0 % (males 2.2% and females 1.5%). The mortality rate was higher in heroin users than among amphetamine users, HR 1.96, controlled for age and other risk factors. The mortality rate among individuals infected with the human immunodeficiency virus (HIV) was high (4.9 %), HR 2.64, compared with HIV-negative individuals. Most of the deaths were from other causes than acquired immune deficiency syndrome. One-third of deaths (227) were caused by heroin intoxication. The number of deaths from HIV-related causes decreased after 1996, when highly active anti-retroviral therapy was introduced. In all, there were 92 HIV-related deaths. Deaths from natural causes increased during the observation period. The SMR was highest for cardiovascular and gastrointestinal diseases. The results indicate a correlation between amphetamine use and death from cerebral haemorrhage. A high proportion of natural deaths were alcohol-related.

Conclusions: The death rate among illicit drug users was persistently high. Alcohol consumption was a contributing factor to premature death.

Keywords: Alcohol; HIV infection; amphetamine; causes of death; cohort study; heroin; mortality; substance abuse.