Rates and correlates of mortality amongst heroin users: findings from the Australian Treatment Outcome Study (ATOS), 2001-2009.

The study aimed to determine mortality rates, standardised mortality ratios (SMRs), and correlates of mortality amongst the Australian Treatment Outcome Study (ATOS) cohort of 615 heroin users over the period 2001-2009. The cohort was followed for a total of 4820.1 person years. A total of 31 deaths (5% of the cohort) occurred across follow-up. The mean age at death was 34.5 years, and 58% were male. The most common cause of death was overdose (68%). The crude mortality rate was 6.43 per 1000 person years, with no gender difference, and the SMR was 4.56 (males=2.95, females=18.57). The only significant bivariate (hazard ratio=3.69) and multivariate (adjusted hazard ratio=3.03) correlate of mortality was a history of opioid overdose prior to baseline. Mortality rates were lower than those seen outside Australasia. Screening for overdose by those treating heroin users would be appropriate, and may contribute to reductions in overall mortality.