Air Pollution and Appendicitis
Bibliographic record
Abstract
Purpose: Adult onset appendicitis is a common condition whose pathogenesis is unclear and almost universally requires surgery. Air pollution is a byproduct of industrialization that causes health effects, in part, through inflammation. We set out to evaluate whether exposure to air pollution was associated with an increased incidence of adult-onset appendicitis. Methods: We designed a population-based study, using a validated (88% accurate) administrative definition of appendicitis, to identify all adults (age > 18 years) who developed appendicitis in Calgary from 1999–2005. Environmental data from fixed site monitoring stations were used to calculate the daily mean levels for ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and particulate matter with a median diameter <10 microns (PM10) and <2.5 (PM2.5). To study the association between air pollutants and appendicitis we used a case-crossover design whereby the case's exposure at the index time (date of admission) was compared to their exposure at referent time intervals. A time-stratified approach to the selection of control intervals was used. The time lags for pollution levels used were the day before and the 5-day average before admission. Conditional logistic regression was used to estimate the adjusted odds ratios (aORs) and 95% confidence intervals (CI) relative to an increase in the interquartile range (IQR) of each pollutant. Secondarily we stratified our analysis by gender and season. Results: Between 1999 and 2005, 4401 adult residents were admitted for appendicitis. Nearly 55% of appendicitis patients were between the ages of 18 and 35, 53.1% were men, and 52.6% occurred in the summer. The aORs associated with an increase in the IQR of the day before admission for appendicitis was significantly elevated for O3 (Table 1). For the 5-day average before admission O3, NO2, SO2, and PM10 were significantly associated with appendicitis (Table 1). The effect of O3 (aOR 1.30; 95% CI: 1.12–1.50), SO2 (aOR 1.18; 95% CI: 1.01–1.39), and PM10 (aOR 1.15; 95% CI: 1.04–1.27) were greatest during the summer. Men were more likely to be affected by SO2 (1.17, 1.03–1.33 versus 1.04, 0.91–1.19), O3 (1.28, 1.10–1.48 versus 1.14, 0.98–1.33), and PM10 (1.13, 1.03–1.23 versus 1.08, 0.97–1.19).Table: Risk of Appendicitis Relative to an Increase in the Interquartile Range of Air PollutantsConclusion: Adults who were exposed to higher levels of O3, NO2, SO2, or PM10 were more likely to be admitted to hospital for appendicitis. For O3, SO2, and PM10 this effect was more pronounced in the summer, when individuals are more likely to be outside. If the association between air pollution and appendicitis in adults is confirmed, then these findings may provide insight into the pathogenesis of appendicitis and offer the potential for prevention through air quality control.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".