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Record W4412688479 · doi:10.1136/bmjph-2024-002394

Circumstances surrounding opioid toxicity deaths within shelters in Ontario, Canada, before and during the COVID-19 pandemic: a population-based descriptive cross-sectional study

2025· article· en· W4412688479 on OpenAlexafffundabout
Bisola Hamzat, Pamela Leece, Daniel McCormack, Alice Holton, Zoë Dodd, Michelle Firestone, Ashley Smoke, Brett Wolfson‐Stofko, Jason Sereda, Jase Watford, Tyler W. Watts, Tara Gomes

Bibliographic record

VenueBMJ Public Health · 2025
Typearticle
Languageen
FieldMedicine
TopicOpioid Use Disorder Treatment
Canadian institutionsNeighbourhood Pharmacy Association of CanadaOntario Stroke NetworkMultiple Sclerosis Society of CanadaOntario Drug Policy Research NetworkUniversity of TorontoUniversity Health NetworkInstitute for Clinical Evaluative SciencesPublic Health OntarioSt. Michael's Hospital
FundersStrategy for Patient-Oriented ResearchCanadian Institutes of Health ResearchMinistry of Health, Ontario
KeywordsPandemicMedicinePopulationCross-sectional studyEnvironmental healthDemographyCoronavirus disease 2019 (COVID-19)DiseaseInfectious disease (medical specialty)Internal medicine

Abstract

fetched live from OpenAlex

Introduction: Evidence suggests growing opioid-related toxicity deaths within shelters that has been exacerbated by the COVID-19 pandemic. We sought to characterise opioid-related toxicity deaths within Ontario shelters before and during the pandemic. Methods: A descriptive cross-sectional study of people who died of an accidental opioid toxicity, where the location of the incident (ie, toxicity) was within a shelter in Ontario, Canada, was conducted. The primary analysis was restricted to conventional shelter spaces as classified by the coroner (ie, excluding temporary COVID-19 emergency shelters in hotels). Characteristics, circumstances surrounding death and patterns of healthcare use preceding death in the pre-pandemic period (1 January 2018-16 March 2020) and the COVID-19 pandemic period (17 March 2020-31 May 2022) were summarised. Results: Overall, opioid-related toxicity deaths within Ontario shelters more than tripled when comparing the pre-pandemic (n=48) with the pandemic period (n=162). Fentanyl directly contributed to the majority of these deaths, and its role as a direct contributor to death rose during the pandemic (from 85.4% to 94.4%; p=0.04), as did those of any stimulants (from 43.8% to 71.0%; p< 0.001). Moreover, benzodiazepine detection in opioid-related toxicity deaths increased during the pandemic (from 27.1% to 56.8%; p<0.001). In both the pre-pandemic and pandemic periods, more than half of the recorded deaths occurred among people with a diagnosis of an opioid use disorder (59.6% vs 53.5%; p=0.46), and a large percentage of people had a healthcare encounter in the week before death (46.8% vs 43.9%; p=0.73). Conclusions: Opioid-related toxicity deaths within Ontario's shelters have increased rapidly over the study period, with notable changes in the circumstances of death and patterns of non-pharmaceutical opioid involvement during the COVID-19 pandemic period. This study demonstrates the urgent need to expand programme and policy interventions tailored toward harm reduction within Ontario's shelter system.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.001
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.089
Threshold uncertainty score0.178

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.003
Science and technology studies0.0020.001
Scholarly communication0.0010.001
Open science0.0010.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0020.000

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.

Opus teacher head0.066
GPT teacher head0.368
Teacher spread0.302 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

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Citations0
Published2025
Admission routes3
Has abstractyes

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