Substance-related acute toxicity deaths in Canada from 2016 to 2017: A protocol for a retrospective chart review study of coroner and medical examiner files (Preprint)
Authors: Rotondo Jenny , VanSteelandt Amanda , Kouyoumdjian Fiona , Bowes Matthew J , Kakkar Tanya , Jones Graham , Abele Brandi , Murray Regan , Schleihauf Emily , Halverson Jessica , Leason Jennifer , Huyer Dirk , Jackson Beth , Bozat-Emre Songul , Shah Devanshi , Rees Erin E 
Published: June 2023

BACKGROUND

Canada continues to experience a national overdose crisis. While studies are available at the regional and provincial/territorial (P/T) levels, detailed national data regarding the burden and context of substance-related acute toxicity deaths is limited, particularly in sub-populations. In response to the overdose crisis, the Public Health Agency of Canada (PHAC), in collaboration with P/T ministries of health and chief coroner and chief medical examiner offices, has undertaken a national chart review study.

OBJECTIVE

This study was conducted to describe and compare the characteristics of substance-related acute toxicity deaths that occurred in Canada between January 1, 2016, and December 31, 2017, including a description of those who have died, the substances involved, and the circumstances surrounding their death. This paper describes the study methodology in detail.

METHODS

This retrospective population-based cross-sectional study involved the review of coroner and medical examiner files for deaths that met the study case definition. Data were collected on demographic and socioeconomic characteristics, medical and substance use history, proximal circumstances surrounding the death, and toxicology findings using a standardized data collection tool that underwent two pilot studies. Data abstractors underwent training, and adherence to data quality standards was assessed. Data were linked to national datasets to allow for the examination of area-level geographic and socioeconomic characteristics. Descriptive analyses will examine differences across subpopulations and with the general Canadian population, where possible. Latent class, spatiotemporal, qualitative, and premature death analyses are also planned. Where possible, analyses will be stratified by manner of death and sex.

RESULTS

The study began in the summer of 2018 and abstraction was delayed due to the COVID-19 pandemic. All activities are expected to be completed by early 2024. A total of 9,414 coroner and medical examiner files met the study case definition. In general, core study variables, including geographic variables and substances contributing to death, had very good availability. Study variables related to the person’s health, history of substance use, and events surrounding the acute toxicity event were available for most records. Socioeconomic variables and those describing socially constructed identities and potentially traumatic life events were mostly unavailable.

CONCLUSIONS

This study provides the most detailed national information on substance-related acute toxicity deaths in Canada to date and can serve as a pre-COVID-19 pandemic baseline for assessing the evolution of the overdose crisis. Results can inform policies and programs to address the overdose crisis, the development of common approaches to medicolegal death investigations, and future research activities.

CLINICALTRIAL

Not applicable