Causes of death of patients with substance dependence: a record-linkage study in a psychiatric hospital in Taiwan

Aims. The causes of death among a series of patients with substance dependence were investigated. Setting. A psychiatric teaching hospital in Taipei, Taiwan (Taipei City Psychiatric Center). Participants. A total of 1698 patients with various diagnostic categories of substance dependence, who had been admitted to TCPC for detoxification were followed-up from 1985 to 1996. Design. A record-linkage study was performed using the patient's national identification number to link between TCPC chart records and the mortality file compiled by the National Department of Health. Risk factor analyses for mortality included socio-demographic data, clinical diagnosis and cause of death. Findings. A total of 141 patients died during the study period. Among them, 83 had a diagnosis of alcohol dependence, 41 of heroin dependence and the remaining 17 cases of sedative, glue or hallucinogen dependence. The annual mortality rate of patients with heroin dependence was 1.94%. Accidental death is the leading cause of death among patients with heroin dependence. However, the patients with alcohol dependence had a higher mortality risk than those with heroin dependence (relative hazard = 1.91, p<0.001) in this study. The proportion of non-violent death was significantly higher among the patients with alcohol dependence than those with heroin dependence (p<0.005). Conclusion. The causes of death among patients with substance dependence found in this Taiwanese series were very similar to those reported in the western literature. However, differences included the absence of death among heroin addicts due to HIV-related disease and a markedly high percentage of alcoholic patients who died of liver diseases.