Hidden suicides. Comparing drug death rates in Canada and Australia

Abstract

Purposes World suicide rates are underestimated, largely due to misclassification of suicides. Our study aimed to compare recent changes in rates of suicide and of deaths that could have been ‘hidden suicides’ in Canada and Australia, where drug death rates are relatively high. When suicides are mis-coded (using ICD-10) it is most commonly as unintentional, unknown cause (R99) or event of undetermined intent (EUI). Method Statistics Canada and the Australian Bureau of Statistics provided underlying cause-of-death data regarding deaths between 2000 and 2022, coded as natural, or of unknown cause, or external cause (including suicides, accidents, and events of undetermined intent). Rates in the two nations were compared, with particular focus on ‘deaths from drug self-intoxication’. Results Graphs show changes in drug death rates in Canada and Australia between 2000 and 2022. By 2017, Canada’s rate was double Australia’s. Their suicide rates (total and drug) were similar but Canada’s declined after 2019. R99 and EUI death rates were higher in Canada; EUI drug death rates are now low in both. Conclusion There is evidence of high rates of ‘hidden’ drug suicide in Canada. Insufficient research has been conducted regarding background factors that lead people to self-intoxicate and thus (in many cases) kill themselves. Stringent policies regarding establishing intentionality have resulted in misclassification of drug suicides as unintentional. Better integration between addiction and mental health services and assiduous investigation of drug overdose deaths (including increased use of psychological or verbal autopsy) will help identify overdose suicides and facilitate preventive strategies.