Ambient sulphur dioxide exposure and emergency department visits for migraine in Vancouver, Canada
Bibliographic record
Abstract
OBJECTIVES: Ambient exposure to sulphur dioxide (SO2) has been previously associated with emergency department (ED) visits for migraine headaches. In the present study, the objective was to examine the relationship between ED visits for migraine and ambient sulphur dioxide concentrations. DESIGN AND METHODS: This was a time-series study of 1059 ED visits for migraine (ICD-9: 346) recorded at a Vancouver hospital between 1999 and 2003 (1 520 days). Air pollution levels of SO2 were measured by fixed-site monitoring stations. The generalized linear mixed models technique was applied to regress daily counts of ED visits for migraine on the levels of the pollutant after adjusting for meteorological conditions: temperature and relative humidity. The analysis was stratified by season and gender. RESULTS: Positive and statistically significant correlations were observed for SO2 exposure and ED visits for migraine for females during colder months (October-March). The percentage increase in daily visits was 16.8% (95% CI: 1.2-34.8) for a 4-day average (of daily mean concentrations) SO2 level, for an interquartile range (IQR) increase of 1.9 ppb. CONCLUSIONS: Our findings provide additional support for a consistent correlation between migraine headache and air pollution (SO2).
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".