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
Bibliographic record
Abstract
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.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.005 |
| Science and technology studies | 0.005 | 0.001 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.002 | 0.003 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".