Table 2

Short-term effect of air pollution on acute exacerbations

ExposureIncreaseHR (95% CI)p Value
O310 µg/m31.47 (1.13 to 1.92)0.005
NO210 µg/m30.92 (0.68 to 1.24)0.584
PM1010 µg/m30.80 (0.52 to 1.27)0.347
PM2.510 µg/m31.29 (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.