Basic characteristics of COPD cohorts
| Nottingham | ECLIPSE: cell numbers | ECLIPSE: emphysema score | |
| Male (%) | 80.0 | 63.2 | 67.0 |
| Age (years) | 59.4±3.1 | 64.0±0.4 | 63.6±0.2 |
| Smoking (pack-years) | 60.6±7.1 | 50.9±1.6 | 50.4±0.7 |
| FEV1 (% predicted) | 59.0±7.3 | 49.2±0.9 | 47.7±0.4 |
| FEV1/FVC (%) | 55.45±4.0 | 43.81±0.7 | 44.7±0.3 |
| N | 10 | 232 | 1427 |
COPD, chronic obstructive pulmonary disease; ECLIPSE, Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.