Overdose mortality incidence and supervised consumption services in Toronto, Canada: an ecological study and spatial...

Area of Science:

• Public Health
• Epidemiology
• Spatial Analysis

Background:

• Supervised consumption services (SCS) are known to prevent onsite overdose deaths.
• Their impact on population-level overdose mortality remains less understood.
• This study investigates the spatial association between SCS and overdose mortality in Toronto, Canada.

Purpose of the Study:

• To characterize overdose mortality trends in Toronto.
• To determine the spatial relationship between SCS locations and overdose mortality events.
• To assess the impact of SCS implementation on neighborhood-level overdose mortality rates.

Main Methods:

• Ecological study and spatial analysis comparing overdose mortality rates before and after SCS implementation.
• Utilized coroner's data for accidental deaths involving psychoactive substances in Toronto.
• Employed geographically weighted regression to model the association between SCS proximity and overdose mortality incidence.

Main Results:

• Included 787 overdose mortality events in Toronto between May 2017 and December 2019.
• Overdose mortality rates significantly decreased in neighborhoods with SCS (8.10 to 2.70 deaths per 100,000).
• Geographically weighted regression indicated a significant inverse association between SCS proximity and overdose mortality, strengthening from 2018 to 2019.

Conclusions:

• SCS implementation in Toronto was associated with reduced overdose mortality in surrounding neighborhoods.
• The protective effect of SCS on overdose mortality increased from 2018 to 2019.
• Policymakers should consider implementing and sustaining SCS in high-overdose mortality areas.