Descriptive statistics for the exposure data included in the analysis (repeated measurements for 76 COPE participants)
| Exposure variable | Person-days | Mean (SD) | Min. | 25th percentile | Median (IQR) | 75th percentile | Max. | |
| NO2 (ppb) | PeT | 10 210 | 7.9 (6.1) | 0.3 | 4.3 | 6.6 (5.5) | 9.7 | 76.5 |
| PeIG | 10 116 | 4.0 (5.2) | 0.0 | 1.4 | 2.6 (3.5) | 4.9 | 71.8 | |
| PeOG | 10 116 | 4.0 (2.9) | 0.2 | 2.2 | 3.3 (2.8) | 5.0 | 69.8 | |
| Ambient | 9995 | 16.9 (8.9) | 1.0 | 10.5 | 15.6 (11.1) | 21.5 | 69.2 | |
| PM2.5 (µg/m³) | PeT | 9636 | 12.1 (13.8) | 0.1 | 5.3 | 8.4 (8.7) | 14.0 | 278.2 |
| PeIG | 9375 | 6.8 (12.2) | 0.0 | 1.7 | 3.8 (5.9) | 7.6 | 267.9 | |
| PeOG | 9369 | 5.5 (8.2) | 0.0 | 2.1 | 3.4 (3.8) | 6.0 | 378.4 | |
| Ambient | 9609 | 13.2 (10.7) | 2.3 | 6.7 | 9.5 (8.7) | 15.4 | 122.0 | |
| CO (ppm) | PeT | 10 209 | 0.12 (0.10) | 0.0 | 0.1 | 0.1 (0.08) | 0.1 | 4.1 |
| PeIG | 10 174 | 0.06 (0.06) | 0.0 | 0.0 | 0.0 (0.06) | 0.1 | 0.9 | |
| PeOG | 10 174 | 0.06 (0.06) | 0.0 | 0.0 | 0.1 (0.03) | 0.1 | 3.5 | |
| Ambient | 10 137 | 0.19 (0.13) | 0.1 | 0.1 | 0.2 (0.09) | 0.2 | 2.0 | |
| O3 (ppb) | PeT | 10 210 | 6.4 (4.7) | 1.0 | 3.3 | 5.2 (4.8) | 8.1 | 57.5 |
| PeIG | 9828 | 2.8 (3.2) | 0.0 | 1.0 | 2.0 (2.7) | 3.6 | 54.5 | |
| PeOG | 9828 | 4.4 (3.6) | 0.0 | 2.2 | 3.5 (3.3) | 5.5 | 51.6 | |
| Ambient | 9269 | 32.8 (13.1) | 0.4 | 25.3 | 33.8 (15.4) | 40.7 | 95.6 | |
COPD, chronic obstructive pulmonary disease; COPE, characterisation of COPD exacerbations using environmental exposure modelling; PeIG, personal exposure to indoor generated pollution; PeOG, personal exposure to outdoor generated pollution; PeT, total personal exposure.