Background: Identifying differences in unintentional versus intentional drug poisoning deaths can inform targeted prevention. This study aimed to: compare unintentional versus intentional drug poisoning deaths by drug involvement, age and sex; describe patterns of drug involvement by intent; and describe common drug patterns by age and sex.

Methods: Cases comprised deaths among Australians aged ≥15 where drug poisoning was the underlying cause (Cause of Death Unit Record File 2012-2016). Sex, age, and drug involvement were analysed by intent using logistic regression.

Results: Of 7994 deaths, 71% were unintentional and 24% intentional. Compared with unintentional deaths, intentional deaths were more likely among females (OR 1.31 [95% CI 1.16-1.48]) and those aged 55+ (1.50 [1.25-1.81] for 55-64 years; 3.79 [3.07-4.66] for 65+ years, compared to 35-44 years), and were more likely to involve hypnosedatives (2.11 [1.87-2.39]), other psychotropic medicines (1.58 [1.39-1.78]), non-opioid analgesics and anaesthetics (1.48 [1.25-1.73]). Common unintentional profiles comprised: opioids (excluding heroin); heroin; alcohol; opioids with hypnosedatives; opioids with hypnosedatives and other psychotropic medicines; stimulants; other psychotropic medicines; and opioids with other psychotropic medicines. Unintentional deaths involving heroin or stimulants only had a greater proportion of males (79.0% and 83.4%, respectively) and younger individuals aged 15-34 (30.3% and 39.5%, respectively). Common intentional profiles comprised: hypnosedatives; other psychotropic medicines; opioids (excluding heroin); hypnosedatives with other psychotropic medicines; opioids with hypnosedatives; and opioids with hypnosedatives and other psychotropic medicines.

Conclusion: The demographic and drug involvement profile of intentional and unintentional deaths were distinct, suggesting different approaches to prevention are necessary.