Short-term effect of air pollution on acute exacerbations
| Exposure | Increase | HR (95% CI) | p Value |
| O3 | 10 µg/m3 | 1.47 (1.13 to 1.92) | 0.005 |
| NO2 | 10 µg/m3 | 0.92 (0.68 to 1.24) | 0.584 |
| PM10 | 10 µg/m3 | 0.80 (0.52 to 1.27) | 0.347 |
| PM2.5 | 10 µg/m3 | 1.29 (0.65 to 2.57) | 0.463 |
Cox proportional hazards model adjusted on season, FVC% predicted at baseline, DLco% predicted at baseline and smoking status.
NO2, nitrogen dioxide; O3, ozone; PM10 and PM2.5, particles with a 50% cut-off aerodynamic diameter of 10 µm and 2.5 µm.