One-pollutant model | Two-pollutant model | Two-pollutant model | Two-pollutant model | |
OR* (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | |
n† | 189 | 189 | 189 | 189 |
PM10 (μg/m3) | 1.21 (0.99 to 1.48) | 1.13 (0.88 to 1.45) | 1.16 (0.90 to 1.48) | 1.23 (0.96 to 1.57) |
NO2 (ppb) | 1.46 (1.05 to 2.02)‡ | 1.34 (0.90 to 1.99) | ||
NOx (ppb) | 1.31 (1.01 to 1.68)‡ | 1.21 (0.89 to 1.64) | ||
CO (ppm) | 1.27 (0.86 to 1.89) | 1.03 (0.64 to 1.6) |
CO, carbon monoxide; NOx, nitrogen oxide; NO2, nitrogen dioxide; PM10, particulate matter <10 μm in diameter.
*Odds ratios estimated per IQR of a pollutant and 3-day mean (lag 2–4 days) adjusted for age, gender, exposure to smoking, paternal asthma history, temperature and season.
†Number of COPSAC children in the model.
‡p<0.05.