Highlights from an analysis of area-based characteristics of substance-related acute toxicity deaths in Canada

Full article available: Baddeliyanage R, Enns A, Vansteelandt A, Abele B, Kouyoumdjian F, Schleihauf E, Pan SY, Steensma C, Rotondo J. Substance-related acute toxicity deaths by area-based characteristics: A descriptive analysis of a national chart review study of coroner and medical examiner data. International Journal of Mental Health and Addiction. 2024 Feb 23:1-24.

Summary

Background

Substance-related acute toxicity deaths (ATDs) (sometimes called 'overdose' or 'poisoning' deaths) continue to be a serious public health concern in Canada. Although ATDs affect people living in all communities across Canada, some groups are more likely to experience ATDs. This may be related to location (such as, more urban and more rural or remote locations), demographics (such as age, sex, and race), and socioeconomic circumstances (such as, income, employment, and education). Studies looking at differences between communities have found higher rates of acute toxicity events and deaths in neighbourhoods with higher levels of deprivation, which refers to the "inability for individuals and communities to attain basic resources and services"^Footnote 1 such as food, housing, work, education, or social connection.

The study

This analysis describes the distribution of ATDs in Canada between 2016 and 2017 across rural and urban locations, by neighbourhood-level indicators of deprivation, and by levels of community remoteness. Coroner and medical examiner data from a national chart review study of ATDs were linked to the Statistics Canada Postal Code Conversion File Plus (PCCF+), the Canadian Index of Multiple Deprivation (CIMD), and the Index of Remoteness. The aim of this analysis was to examine ATDs by i) community sizes and metropolitan influence zones, ii) area-level deprivation, as measured by the four dimensions of the CIMD (residential instability, economic dependency, ethno-cultural composition, and situational vulnerability), and iii) levels of remoteness (easily accessible, accessible, less accessible, remote, or very remote areas).

Key findings

Among people who died in Canada of substance-related acute toxicity in 2016 and 2017, deaths varied by community population sizes, neighbourhood-level indicators of deprivation, and levels of area remoteness:

• The highest percentage of deaths was among people who resided in the largest urban communities with 1,500,000 or more residents (Toronto, Montreal, and Vancouver), making up 30% of deaths.
• The highest rate of death was among people who resided in mid-sized urban communities with 100,000 to 499,999 residents and people who lived in accessible areas.
• The highest percentage of deaths and rate of deaths were among people who resided in neighbourhoods with the highest levels of residential instability (neighbourhood population changes), and situational vulnerability (housing challenges, lower education, and population identifying as Indigenous).

Study limitations

As information collected from coroner and medical examiner charts is used to support death investigations and not for research purposes, information abstracted into the data collection tool was not always consistently available. There were higher proportions of missing postal code data from British Columbia and Quebec due to data collection limitations. Cases where both the postal code and municipality of residence were not available were excluded from this analysis as they could not be linked with the PCCF +, CIMD, and Index of Remoteness.

Acknowledgements

We would like to acknowledge our collaborators at the offices of chief coroners and chief medical examiners across Canada for providing access to their death investigation files and the co-investigator team Erin Rees, Matthew Bowes, Songul Bozat-Emre, Jessica Halverson, Dirk Huyer, Beth Jackson, Graham Jones, Jennifer Leason, and Regan Murray for their contributions to developing the national chart review study on substance-related ATDs. Opinions and conclusions in this report are the authors' own and are not endorsed or approved by data providers or funders.

Disclaimer

This report is based on data and information compiled and provided by the offices of chief coroners and chief medical examiners across Canada, and Statistics Canada. However, the analyses, conclusions, opinions, and statements expressed herein are those of the authors, and not necessarily those of the data providers.