MétaCan
Menu
Back to cohort
Record W4412015616 · doi:10.1027/0227-5910/a001015

Suicide Deaths by Gas Inhalation in Toronto, Canada – An Observational Study of Emerging Methods of Suicide From 1998 to 2020

2025· article· en· W4412015616 on OpenAlexaffabout
Vera Yu Men, Prudence Po Ming Chan, Ayal Schaffer, Rosalie Steinberg, Rachel Mitchell, Jennifer M. Dmetrichuk, Paul Yip, Simon Hatcher, Mark Sinyor

Bibliographic record

VenueCrisis · 2025
Typearticle
Languageen
FieldPsychology
TopicSuicide and Self-Harm Studies
Canadian institutionsOttawa HospitalUniversity of OttawaUniversity of TorontoOffice of the Chief Medical ExaminerHealth Sciences CentreSunnybrook Health Science Centre
Fundersnot available
KeywordsSuicide methodsCoronerSuicide preventionPoison controlMedicineInjury preventionOccupational safety and healthDemographyMedical emergencyPsychiatryEnvironmental healthSuicide rates

Abstract

fetched live from OpenAlex

Abstract: Background: Inert gases are an emerging means of suicide in Toronto, Canada. Trends in suicide by these methods change over time, yet long-term patterns remain uncharacterized in cities like Toronto. Aims: To update trends in suicide using inhalational gas and explore the profiles of individuals using different methods in Toronto. Methods: Suicide deaths were identified from coroner’s records and classified by suicide methods. Time trends were explored, and bivariate analyses were performed to characterize differences in profiles between groups. Results: There were 229 suicide deaths by inert gas between 1998 and 2020. For 2016–2020, suicide by nitrogen increased by 100%, whereas there was a decrease in suicide by helium (−38%) and charcoal burning (−57%) compared to 2011–2015. Males comprised a higher proportion of inhalational gas deaths compared to other methods. Individuals who died by compressed gas and charcoal burning were more likely to have left suicide notes compared to people who died by other methods. Limitations: The number of suicide deaths by gas inhalation may be underestimated due to potential misclassification. Conclusions: Suicide prevention strategies including restricting access to suicidal means, providing helpline information on the products, and responsible media reporting should each be advocated for.

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)0.001
metaresearch head score (Gemma)0.003
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 score0.034
Threshold uncertainty score0.247

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.003
Meta-epidemiology (narrow)0.0000.001
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0020.006
Science and technology studies0.0030.001
Scholarly communication0.0010.001
Open science0.0010.001
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0030.000

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 head0.089
GPT teacher head0.438
Teacher spread0.349 · 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".

Quick stats

Citations1
Published2025
Admission routes2
Has abstractyes

Explore more

Same venueCrisisSame topicSuicide and Self-Harm StudiesFrench-language works237,207