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Record W4410133110 · doi:10.1093/occmed/kqaf017

Incidence of severe COVID-19 among 1.2 million workers in Ontario, Canada

2025· article· en· W4410133110 on OpenAlexafffundabout
Jeavana Sritharan, Chaojie Song, Marianne Harris, Tracy L Kirkham, Brendan T. Smith, John Kim, Victoria H Arrandale, Paul A. Demers

Bibliographic record

VenueOccupational Medicine · 2025
Typearticle
Languageen
FieldMedicine
TopicInfection Control and Ventilation
Canadian institutionsToronto Metropolitan UniversityOccupational Cancer Research CentrePublic Health OntarioUniversity of Toronto
FundersWorkplace Safety and Insurance Board
KeywordsCoronavirus disease 2019 (COVID-19)Incidence (geometry)2019-20 coronavirus outbreakSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2)MedicineBetacoronavirusEnvironmental healthEpidemiologyDemographyVirologyOutbreakInternal medicineDisease

Abstract

fetched live from OpenAlex

BACKGROUND: The disproportionate impact of coronavirus disease (COVID-19) on healthcare workers has been highlighted; however, there is a lack of evidence regarding other high-risk occupations and industries. AIMS: This study estimated the risk of severe COVID-19 among a large cohort of workers in Ontario, Canada. METHODS: This study used a cohort of 1.2 million workers identified using workers' compensation claims records (1983-2019). Identified workers were linked with emergency department (ED) visits and hospitalizations (2020-2021). Cases coded as U0.71 (virus detected, confirmed case) were identified from ED visits and hospitalizations. Hazard ratios (HRs) and 95% confidence intervals (CI95%) for COVID-19 for each occupational group compared to all other workers in the cohort were calculated, adjusting for age and birth year. Standardized incidence ratios and 95% CI, comparing workers to the general population of Ontario were also calculated, adjusting for age, sex, year and region. RESULTS: A total of 10 322 severe COVID-19 cases among workers were identified through ED visits and hospitalizations. Workers in material handling (HR=1.32, CI95%=1.21-1.43), medicine and health (HR=1.27, CI95%=1.18-1.37), processing (food, water, textile) (HR=1.23, CI95%=1.12-1.36) and machining occupations (HR=1.11, CI95%=1.02-1.20) had some of the highest risks of COVID-19 when compared to all other workers in the cohort. Findings were somewhat consistent when comparing workers to the general population of Ontario. CONCLUSIONS: Certain groups of workers in this cohort demonstrated elevated risks of severe COVID-19. The findings align with previous studies and emphasize the need to include occupational surveillance methods in future pandemic preparedness in Canada.

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 distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.001
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesInsufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.013
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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 head0.018
GPT teacher head0.301
Teacher spread0.284 · 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 teacher head, not a consensus.

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

Citations0
Published2025
Admission routes3
Has abstractyes

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