Highlights from phase one of the national study on opioid and other drug-related overdose deaths: insights from coroners and medical examiners

Suggested citation

Special Advisory Committee on the Epidemic of Opioid Overdoses. Highlights from phase one of the national study on opioid- and other drug-related overdose deaths: insights from coroners and medical examiners. Ottawa: Public Health Agency of Canada; September 2018. Updated October 2019.

Key findings
  • Coroners, medical examiners, and toxicologists described how opioid- and other drug-related overdose deaths have occurred across all sociodemographic and socioeconomic groups
  • Characteristics more frequently observed among those who died included:
    • a history of mental health concerns, substance use disorder, trauma, and stigma
    • decreased drug tolerance
    • being alone at the time of overdose
    • lack of social support
    • lack of comprehensive and coordinated healthcare and social service follow-up
  • Polysubstance use was described as a key contributing factor

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In recent years, opioid- and other drug-related overdose deaths have increased sharply and become a significant cause of mortality in Canada. In response, local governments, provinces, and territories have implemented a variety of interventions and the Government of Canada has committed to a targeted public health response supported by a strong evidence base which includes the enhancement of relevant surveillance and research activities.

Why was this study conducted?

Though we now have national data to measure the magnitude, distribution, and trends of apparent opioid-related deaths in Canada, we sought to better understand the situation beyond the numbers in order to inform the response and maximize the impact of interventions. A two-phased study was developed in collaboration with provinces and territories. In the first phase, coroners and medical examiners from across Canada were interviewed to describe those who are dying from opioid and other drug-related overdoses and the circumstances surrounding their deaths.

Coroners and medical examiners gain a unique perspective during the course of their investigations to determine who died and how, when, where, and why the death occurred. They gather information from a variety of sources including family, friends, neighbours, service providers, health and other records, post-mortem examinations, and the scene of death. Some coroners and medical examiners have gained considerable insight on changes over time from investigating overdose deaths for many years. Toxicologists play an important role in these death investigations through their analysis of body fluids for the presence of drugs. Our study draws on this information source to glean observations and insights from these experts by allowing them to use their own words to describe the manner and circumstances surrounding these ultimately preventable deaths.

This short report highlights some of the key findings of this qualitative study. An article will be published in a peer-reviewed journal describing the study methodology and findings in greater detail. A second phase of this study will involve reviewing the written coroner and medical examiner records of all drug- and alcohol-related overdose deaths in participating Canadian provinces and territories to better understand the characteristics of those individuals who have died by overdose, the substances involved, and antecedent factors. Together, findings from these studies will complement national surveillance data and other related research activities to provide a more comprehensive picture of this public health crisis in Canada.

How did we carry out the study?

Thirty-six semi-structured interviews were held with coroners, medical examiners, and toxicologists from eight provinces and territories across Canada (British Columbia, Saskatchewan, Manitoba, Ontario, Quebec, New Brunswick, Nova Scotia, and the Northwest Territories) between December 2017 and February 2018.

Coroners, medical examiners, and toxicologists were asked to reflect upon the opioid- and other drug-related overdose deaths they had investigated between 2016 and 2017 to identify common characteristics among those who died, the substances involved, and potential missed opportunities for intervention or prevention. Interview transcripts were reviewed, coded, and grouped to identify key themes.

What did we learn?

All sociodemographic and socioeconomic groups are affected

Many participants described how overdose deaths are not only happening among people with long-term substance use. The profile of people who are dying has changed in recent years; in addition to deaths among individuals with chronic substance use, coroners and medical examiners are now also seeing more deaths among individuals from all sociodemographic and socioeconomic groups, those suffering from chronic pain, and those who use substances occasionally (even for the first time). Nonetheless, some populations experience a greater burden of overdose deaths, as described below.

Mental health, substance use disorder, trauma, and stigma

A history of mental health concerns, substance use disorder, trauma, and stigma were commonly identified by participants. Participants pointed out that some of the individuals who died from an overdose experienced more than one of these factors at the same time. A common theme heard during the interviews referred to deaths involving persons with untreated or undiagnosed mental health concerns.

Reduced drug tolerance

Reduced drug tolerance was identified as a factor by some participants. Examples were provided of people experiencing an overdose after a recent release from incarceration or discharge from a treatment centre. After not being exposed to regular drug use while in these settings, individuals may have a reduced drug tolerance. This can result in a fatal overdose if they return to using substances at previously established levels.

Help unavailable at the time of overdose

Participants described how often the people who had overdosed had consumed drugs while alone, without others nearby who could intervene. Participants also described scenarios where a person had overdosed in the presence of others but those individuals were not aware of the signs of an overdose or were unable to observe and respond to those signs (such as when they were asleep).

Lack of support and coordinated services

Lack of social support was another common theme mentioned by participants. Many of the individuals whose deaths they investigated did not have support from family or friends, were estranged from their family, or lived alone, increasing their vulnerability.

Lack of coordination between comprehensive health and social services was also highlighted by some participants who spoke of individuals commonly interacting with the health care system and other social services shortly before their death.

Polysubstance use

We asked participants about commonly identified substances in the opioid- and other drug-related deaths that they had investigated. A large number of substances were named, with the most common being alcohol, fentanyl, methadone, cocaine, carfentanil, hydromorphone, benzodiazepines, morphine, heroin, and methamphetamines (note that this is not an exhaustive list). While there were a number of similarities across provinces and territories, there were also some regional differences.

Participants from all eight participating provinces and territories identified polysubstance use as an issue. While this was attributed in part to the purposeful consumption of numerous substances, participants described how some of the people who died from an opioid- or other drug-related overdose may not have been aware that the drugs they had purchased also contained a contaminant, such as fentanyl or carfentanil.

Study limitations

Not all coroners and medical examiners were interviewed in each participating province and territory and not all provinces and territories in Canada participated in this study. Notably, one province that has been heavily impacted by the opioid crisis did not participate. Thus the views presented here represent those of only a subset of the death investigation community. Recall bias may have affected responses, with answers reflecting more recent or memorable cases. Also, this study presents a snapshot of the characteristics of those who have died at the time when the interviews took place. As the situation continues to evolve, these characteristics may change.

Though participants in this study did sometimes discuss their personal experiences as the family members, friends, colleagues, care providers, or service providers of those who died, this study focused on the professional perspectives of these participants and did not endeavour to understand the perspectives gained from personal experiences. Furthermore, this study did not look at non-fatal overdoses involving opioids or other substances. Additional research studies are necessary to address these priority information needs.


We would like to thank all of the participants from the British Columbia, Saskatchewan, Manitoba, Ontario, Quebec, New Brunswick, Nova Scotia, and Northwest Territories Coroner and Medical Examiner Offices for taking the time to share their knowledge and thoughtful reflections on their experiences. We also thank all members of the Opioid Overdose Surveillance Task Group and the Forum of Chief Coroners and Medical Examiners for their input and feedback.

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