Evaluating the effects of Toronto's supervised consumption sites on crime: multiple baseline interrupted time series analyses with and without synthetic controls

ImportanceBeginning in August 2017, nine overdose prevention sites and supervised consumption sites (OPS/SCS) began operating in Toronto, Canada. Following years of community pushback that these sites increased local crime and disorder, they were closed in March 2025. ObjectiveTo evaluate the population-level effects of OPS/SCS on crime and disorder. Design, Setting, ParticipantsThis two-part ecological study used Toronto Police Service data to compare crime incidence before and after OPS/SCS implementation using interrupted time series analyses with and without controls. We restricted analysis to crimes that occurred within city boundaries between 1 January 2014 and 30 June 2024. Main Outcomes and MeasuresWe used monthly event counts of all assaults, auto thefts, break and enters, robberies, thefts over $5000, bicycle thefts, thefts from motor vehicle and mental health apprehensions as our eight outcomes. We compared incidence within 100m, 200m, and 400m of the geolocation of each OPS/SCS before and after implementation; and repeated analysis using treated and synthetic control neighbourhoods. We pooled estimates for population-level effects. ResultsWithin 400m (approximately a quarter mile), we observed level effects for break and enters (48.87%, 95% CI: 26.15, 75.68%) and bicycle thefts (-19.46%, 95% CI: -30.36, -6.86%) immediately post-implementation. Meanwhile, monthly trends for assaults (-0.5%, 95% CI: -0.92, -0.07%), break and enters (-1.11%, 95% CI: -1.60, -0.61%), robberies (-1.36, 95% CI: -1.96, -0.75%), thefts over $5000 (-1.47%, 95% CI: -2.92, 0.01%), bicycle thefts (-1.54%, 95% CI: -2.44, -0.62%), and thefts from vehicles (-1.59%, 95% CI: -2.58, -0.60%) declined. Pooled neighbourhood analyses showed level-effects for break and enters (18.83%, 95% CI: 1.70, 38.84%) and mental health apprehensions (10.20%, 95% CI: 1.55, 19.60%) post-implementation; and monthly changes in trends for break and enters (-0.46%, 95% CI: - 0.93, 0.01%), auto theft (-0.66%, 95% CI: -1.31, 0.00%), thefts over $5000 (-1.02%, 95% CI: -2.05, 0.03%), and bicycle thefts (-1.07%, 95% CI: -1.58, -0.57%). Site- and neighbourhood-specific results revealed some communities were impacted while others were not. Conclusions and RelevanceThe effects of Torontos OPS/SCS on crime were generally neutral. Break and enters increased immediately post-implementation, but declined with time. Data Sharing AgreementThis study used publicly available data provided by Toronto Police Services. For more information, please visit the Toronto Police Service Public Safety Data Portal at: https://data.torontopolice.on.ca/. For Statistics Canada census tract profiles visit: https://www12.statcan.gc.ca/census-recensement/2021/dp-pd/prof/index.cfm?Lang=E. Key pointsQuestion: What was the effect of overdose prevention sites and supervised consumption sites (OPS/SCS) on crime in Toronto? Findings: Pooled site- and neighbourhood-level random effects models found counts of break and enters increased, but trends in outcomes declined per month. Trends in assaults, robberies, thefts over $5000, bicycle thefts, and thefts from motor vehicles also decreased. Site- and neighbourhood-specific interrupted time series showed some communities were impacted negatively while others were not. Meaning: The effects of Torontos OPS/SCS on crime were generally neutral to positive; break and enters increased immediately post-implementation, but declined with time.