Patient demographics
| BTS group | Sputum group | |
| Subjects n | 40 | 42 |
| Age yrs | 70 (49–80) | 68 (45–82) |
| Male/female | 30/10 | 25/17 |
| Smoking n | ||
| Current smoker | 8 | 12 |
| Ex-smoker | 31 | 30 |
| Never-smoker | 1 | 0 |
| Smoking pack-yrs | 47.5±27.8 | 50.6±30.0 |
| FEV1 L | 1.07±0.44 | 0.96±0.47 |
| FVC L | 2.28±0.84 | 2.11±0.67 |
| Post-bronchodilator FEV1 L | 1.14±0.48 | 1.04±0.50 |
| FEV1 % pred | 38.4±15.5 | 38.1±15.4 |
| TLC % pred | 98.6±15.3 | 99.7±15.4 |
| RV % pred | 123.6±38.1 | 133.1±47.1 |
| KCO % pred | 75.0±17.9 | 65.5±22.9 |
| BMI | 26.1±3.5 | 26.0±0.2 |
| Baseline sputum eosinophil %# | 1.5±0.6 | 1.7±0.6 |
| Blood eosinophils ×109·L−1 | 0.24±0.24 | 0.20±0.15 |
| Exhaled nitric oxide ppb | 5.3±6.5 | 7.6±8.9 |
| Serum IgE# | 61.6±0.7 | 36.3±0.7 |
| Baseline inhaled steroid dose¶ | 1200±1007.6 | 1024±902.2 |
| Patients admitted in previous year n | 12 | 12 |
| Rate of admission in previous year | 0.55±0.7 | 0.43±0.6 |
| Attended pulmonary rehab within 1-yr prior to study n | 10 | 9 |
Data are presented as mean (range) or mean±sd, unless otherwise stated. BTS: British Thoracic Society; FEV1: forced expiratory volume in one second; FVC: forced vital capacity; % pred: % predicted; TLC: total lung capacity; RV: residual volume; KCO: corrected gas transfer; BMI: body mass index; Ig: immunoglobulin. #: Geometric mean; ¶: beclomethasone diproprionate equivalent μg·day−1.