Characteristics and exposures to air pollutants of enrolled subjects with asthma
| All N=2485 | Asthma with exacerbation n=497 | Asthma without exacerbation n=1988 | P value | |
| Demographic data | ||||
| Age (years) | 64.03±15.91 | 64.6±16.29 | 63.89±15.81 | 0.38 |
| Age group | 0.99 | |||
| 20–49 | 436 (17.55%) | 86 (17.30%) | 350 (17.61%) | |
| 50–64 | 666 (26.8%) | 135 (27.16%) | 531 (26.71%) | |
| >=65 | 1383 (55.65%) | 276 (55.53%) | 1107 (55.68%) | |
| Sex (female) | 1740 (70.02%) | 348 (70.02%) | 1392 (70.02%) | 1.00 |
| Index season | ||||
| Spring | 735 (29.58%) | 147 (29.58%) | 588 (29.58%) | 1.00 |
| Summer | 510 (20.52%) | 102 (20.52%) | 408 (20.52%) | |
| Autumn | 535 (21.53%) | 107 (21.53%) | 428 (21.53%) | |
| Winter | 705 (28.37%) | 141 (28.37%) | 564 (28.37%) | |
| Air pollutants 1 day prior to exacerbation | ||||
| PM2.5 (g/m3) | 27.74±16.75 | 28.92±17.73 | 27.45±16.49 | 0.09 |
| PM10 (g/m3) | 49.3±27.24 | 51.26±31.49 | 48.87±26.05 | 0.16 |
| O3 | ||||
| O3 (1-hour maximum, ppb) | 55.64±20.81 | 57.24±20.25 | 55.24±20.94 | 0.05 |
| O3 (8-hour maximum, ppb) | 44.92±17.22 | 46.42±16.91 | 44.54±17.28 | 0.03 |
| O3 (24 hours average, ppb) | 27.75±10.65 | 28.66±10.26 | 27.53±10.74 | 0.03 |
| SO2 (ppb) | 2.83±1.34 | 2.85±1.35 | 2.82±1.34 | 0.67 |
| CO (ppm) | 0.41±0.19 | 0.41±0.19 | 0.40±0.19 | 0.39 |
| NO2 (ppb) | 14.07±6.97 | 14.14±7.05 | 14.05±6.95 | 0.81 |
| Temperature (°C) | 22.32±5.35 | 22.57±5.29 | 22.25±5.37 | 0.24 |
| Relative humidity (%) | 72.76±8.39 | 72.44±8.11 | 72.84±8.46 | 0.33 |
| Comorbidities | ||||
| ACO | 329 (13.2%) | 141 (28.4%) | 188 (9.5%) | <0.01 |
| CCI | 2.89±2.68 | 3.72±2.99 | 2.68±2.56 | <0.01 |
| CCI ≥3 | 861 (34.65%) | 245 (49.3%) | 616 (30.99%) | <0.01 |
Data are presented as mean±SD and N (%).
CCI, Charlson Comorbidity Index; CO, carbon monoxide; NO2, nitrogen dioxide; O3, ozone; PM10, particulate matter <10 µm; PM2.5, particulate matter <2.5 µm; SO2, sulfur dioxide.