Accessibility gaps of physical supervised consumption sites in Canada motivating the use of overdose response technology/phone based virtual overdose response services: a retrospective cohort study.

Background: Overdose response technology or virtual overdose response services are an evolving complementary harm reduction intervention which may overcome certain accessibility barriers of physical supervised consumption sites (SCS) and overdose prevention sites (OPS). We sought to characterize SCS/OPS accessibility barriers among clients accessing a nationwide overdose response phone-based hotline in Canada.

Methods: We performed a retrospective cohort analysis using anonymized call logs of the National Overdose Response Service (NORS) between December 2020 to July 2023. De-identified caller locations were cross-referenced with the locations, policies and operational hours of existing physical SCS/OPS. The primary outcome was accessibility of physical SCS/OPS defined hierarchically according to alignment with caller postal code, substance use routes reported, and calling times.

Findings: Our cohort comprised 4501 calls from 331 unique clients. Despite always having nearby SCS/OPS open and supporting substance use routes of choice, 100 clients (30.2%) preferentially utilized NORS. Among 191 clients (57.7%) who never had access to physical SCS/OPS at time of calling, 92 (27.8%) lacked a nearby site, 58 (17.5%) called outside of operational hours, and 41 (12.4%) would not be permitted to smoke on premises. Secondary analyses identified correlations between accessibility and the urbanicity and geographical region of callers within Canada.

Interpretation: Overdose response technology or virtual overdose response services are a novel complementary harm reduction strategy both for clients with access barriers to physical SCS/OPS and those who prefer virtual services. System-level correlates of client location urbanicity and inter-provincial variation indicate actionable targets for expanding harm reduction services both physical and virtual to better engage with people who use drugs.

Funding: Health Canada Substance Use and Addictions Program, Canadian Institutes of Health Research, and Grenfell Ministries.