Comparison between patients who experience infrequent exacerbations (<2.92 per year) and those who experience frequent exacerbations (>2.92 per year)
| Infrequent | Frequent | ||||
|---|---|---|---|---|---|
| Median (n=63) | IQR | Median (n=46) | IQR | p value Wilcoxon test | |
| FEV1=forced expiratory volume in 1 second; FVC=forced vital capacity; PEF=peak expiratory flow; Pao2; Paco2=arterial oxygen and carbon dioxide tensions. | |||||
| Age (years) | 69.8 | 64.4–73.9 | 65.6 | 58.8–73.5 | 0.088 |
| Body mass index (kg/m2) | 25.2 | 23.1–28.0 | 25.2 | 21.5–29.1 | 0.813 |
| FEV1 (l) | 1.05 | 0.74–1.30 | 0.96 | 0.72–1.35 | 0.988 |
| FEV1 (% predicted) | 38.5 | 26.1–49.8 | 37.7 | 28.0–52.8 | 0.766 |
| FEV1 (% reversibility) | 5.4 | 0–13.6 | 3.6 | 0–12.6 | 0.497 |
| FVC (l) | 2.68 | 1.82–3.00 | 2.38 | 1.86–2.90 | 0.461 |
| FEV1/FVC (%) | 41.9 | 33.1–48.9 | 46.6 | 31.8–53.8 | 0.540 |
| PEF (l/min) | 188 | 147–250 | 210 | 160–300 | 0.129 |
| Pao2 (kPa) | 8.95 | 8.41–9.44 | 9.09 | 7.98–9.57 | 0.578 |
| Paco2 (kPa) | 5.75 | 5.43–6.21 | 5.95 | 5.40–6.44 | 0.306 |
| Smoking (years) | 40 | 30–50 | 41.5 | 30–50.5 | 0.673 |
| % | % | χ2 test | |||
| Male | 79.4 | 67.4 | 0.158 | ||
| Chronic dyspnoea | 30.2 | 65.2 | <0.001 | ||
| Chronic wheeze | 22.2 | 47.8 | 0.005 | ||
| Chronic cough | 42.9 | 58.7 | 0.102 | ||
| Chronic sputum production | 52.4 | 60.1 | 0.378 | ||
| History of smoking | 93.7 | 95.6 | 0.651 | ||
| Current smoking | 22.2 | 39.3 | 0.056 | ||
| Daily inhaled steroid use | 88.7 | 95.7 | 0.186 | ||