OP IV – 6 Associations between daily mortality and ambient no2 and o3 in persons having congestive heart failure: nested case-control analyses using different exposure models
Bibliographic record
Abstract
Background/aim To meet some of the limitations of previous studies using grouped-analysis, we developed a cohort of persons with congestive heart failure and used a nested case-control design to estimate whether daily non-accidental mortality was associated with spatially-resolved, daily exposures to ambient NO2 and O3, and whether these associations were modified according to worsening of health. Methods We constructed the cohort from health databases. For each case we randomly selected 100 controls matching on the calendar day and gender. We assigned daily NO2 (all year) and O3 (May-September) exposures from the following methods to predict spatially-resolved, daily concentrations at participants’ residence: measurements at the nearest monitor; inverse–distance weighting interpolation (IDW); back–extrapolation from a land–use regression model from a dense monitoring survey. We modelled air pollution using DLNMs over lags 0 to 3 days. We adjusted for age and area-based contextual variables, whereas weather and temporal trends were controlled by design. We assessed potential effect modification by some indicators possibly reflecting a worsening of health. Results The cohort included 65 534 individuals followed on average for four years. For NO2 and O3 all response functions were linear. For NO2, we found positive association using the back-extrapolation method (MPC: 3.0%; 95% CI: −0.8% to 7.0%) but negative associations using the nearest station (MPC: −5.5%; 95% CI: −8.0 to −2.8%), and IDW (MPC: −8.8%; 95% CI: −15.0 to −2.1%). For O3, we found positive cumulative effect for the nearest station (6.7%; 95% CI: 0.3% to 13.5%), inverse-distance weighting (18.5%; 95% CI: −2.6% to 44.1%) and back-extrapolation (7.3%; 95% CI: 3.0% to 11.9%). For both pollutants, we found evidence of effect modification according to the prescribed dose of an important drug used to treat heart failure. Conclusion Exposure to ambient NO2 and O3 was associated with daily mortality in congestive heart failure. The methods used to assess daily exposure can have considerable influence on the estimated acute health effects.
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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 | 0.010 | 0.011 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.006 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".