Overall populations at the most recent assessment *: fixed-effect meta-analysis results on model 3 (adjusted for age, sex, smoking, education and season of interview) for all air pollutants and traffic indicators for each outcome, using ESCAPE-period (2008–2011) exposures from all five cohorts.
| Outcome | Chronic bronchitis | Chronic cough | Chronic phlegm | |||
|---|---|---|---|---|---|---|
| Exposure† | OR | phet‡ | OR | phet | OR | phet |
| (95% CI) | (95% CI) | (95% CI) | ||||
| PM2.5 (5 µg/m3) | 0.90 | 0.754 | 0.91 | 0.440 | 0.96 | 0.850 |
| (0.74 to 1.09) | (0.80 to 1.04) | (0.84 to 1.11) | ||||
| PM2.5abs (per 10−5 m−1) | 1.02 | 0.504 | 1.01 | 0.070 | 1.02 | 0.693 |
| (0.85 to 1.22) | (0.89 to 1.15) | (0.88 to 1.18) | ||||
| PM10 (10 µg/m3) | 0.92 | 0.193 | 0.92 | 0.494 | 1.02 | 0.696 |
| (0.75 to 1.13) | (0.80 to 1.06) | (0.87 to 1.18) | ||||
| PMcoarse (5 µg/m3) | 0.99 | 0.165 | 0.99 | 0.737 | 1.07 | 0.131 |
| (0.83 to 1.18) | (0.87 to 1.12) | (0.94 to 1.22) | ||||
| NO2 (10 µg/m3) | 1.00 | 0.973 | 1.05 | 0.953 | 1.01 | 0.656 |
| (0.92 to 1.08) | (0.99 to 1.11) | (0.95 to 1.07) | ||||
| NOx (20 µg/m3) | 1.02 | 0.793 | 1.04 | 0.622 | 1.02 | 0.393 |
| (0.94 to 1.09) | (0.98 to 1.09) | (0.96 to 1.08) | ||||
| Traffic intensity§ | 0.95 | 0.739 | 0.96 | 0.339 | 0.98 | 0.366 |
| (0.75 to 1.19) | (0.80 to 1.14) | (0.82 to 1.17) | ||||
| Traffic load¶ | 0.99 | 0.509 | 0.95 | 0.831 | 0.97 | 0.797 |
| (0.82 to 1.20) | (0.81 to 1.10) | (0.83 to 1.13) | ||||
*Asthma-E3N 2011, ECRHS 1998–2002, NSHD 2008, SALIA 2006–10, SAPALDIA 2002. Due to questionnaire wording SALIA is not included in analyses of phlegm alone.
†Results were interpreted as per exposure unit, as shown in the parentheses.
‡phet: p value for heterogeneity.
§Binary variable, <5000 (reference group) vs >5000 vehs/day.
¶Binary variable, <500 000 (reference group) vs >500 000 vehs m/day.
ECRHS, European Community Respiratory Health Survey; ESCAPE, European Study of Cohorts for Air Pollution Effects; NOx; nitrogen oxides; NSHD, National Survey of Health and Development; PM, particulate matter; SALIA, Study on the influence of Air pollution on Lung function, Inflammation and Aging; SAPALDIA, Swiss cohort study on Air Pollution And Lung and heart Diseases in Adults.