AIMS: To measure the change in proportion of opioid-related overdose deaths attributed to people experiencing homelessness and to compare the opioid-related fatalities between individuals experiencing homelessness and not experiencing homelessness at time of death.

DESIGN, SETTING AND PARTICIPANTS: Population-based, time-trend analysis using coroner and health administrative databases from Ontario, Canada from 1 July 2017 and 30 June 2021.

MEASUREMENTS: Quarterly proportion of opioid-related overdose deaths attributed to people experiencing homelessness. We also obtained socio-demographic and health characteristics of decedents, health-care encounters preceding death, substances directly contributing to death and circumstances surrounding deaths.

FINDINGS: A total of 6644 individuals (median age = 40 years, interquartile range = 31-51; 74.1% male) experienced an accidental opioid-related overdose death, among whom 884 (13.3%) were identified as experiencing homelessness at the time of death. The quarterly proportion of opioid-related overdose deaths attributed to people experiencing homelessness increased from 7.2% (26/359) in July-September 2017 to 16.8% (97/578) by April-June 2021 (trend test P < 0.01). Compared with housed decedents, those experiencing homelessness were younger (61.3 versus 53.1% aged 25-44), had higher prevalence of mental health or substance use disorders (77.1 versus 67.1%) and more often visited hospitals (32.1 versus 24.5%) and emergency departments (82.6 versus 68.5%) in the year prior to death. Fentanyl and its analogues more often directly contributed to death among people experiencing homelessness (94.0 versus 81.4%), as did stimulants (67.4 versus 51.6%); in contrast, methadone was less often present (7.8 versus 12.4%). Individuals experiencing homelessness were more often in the presence of a bystander during the acute toxicity event that led to death (55.8 versus 49.7%); and where another individual was present, more often had a resuscitation attempted (61.7 versus 55.1%) or naloxone administered (41.2 versus 28.9%).

CONCLUSIONS: People experiencing homelessness account for an increasing proportion of fatal opioid-related overdoses in Ontario, Canada, reaching nearly one in six such deaths in 2021.