Baseline spirometric parameters and severity of chronic obstructive pulmonary disease by bronchodilator responsiveness at baseline
| ΔFEV1 ≥12% and ≥200 mL | ΔFEV1 ≥15% | ΔFEV1 ≥10% pred | ||||
| Responsive | Poorly responsive | Responsive | Poorly responsive | Responsive | Poorly responsive | |
| FEV1 % pred | ||||||
| Pre-bronchodilator | 38.5±10.5¶ | 40.3±13.4 | 36.3±10.6¶ | 45.2±12.2 | 38.8±10.0* | 39.7±13.0 |
| Post-bronchodilator | 50.6±11.20¶ | 44.0±13.3 | 47.4±12.4 | 47.9±13.1 | 52.6±10.3¶ | 44.4±13.0 |
| GOLD stage % | ||||||
| Stage II: moderate | 56.0 | 35.4 | 45.7 | 48.1 | 62.7 | 36.3 |
| Stage III: severe | 40.6 | 49.5 | 45.9 | 42.5 | 36.0 | 50.2 |
| Stage IV: very severe | 3.3 | 15.2 | 8.4 | 9.4 | 1.3 | 13.5 |
| p-value# | <0.0001 | <0.001 | <0.0001 | |||
Data are presented as mean±sd, unless otherwise indicated. Δ: change; FEV1: forced expiratory volume in one second; % pred: % predicted; GOLD: Global Initiative for Chronic Obstructive Lung Disease. #: across all GOLD stages shown (versus poorly responsive). *: p<0.05; ¶: p<0.0001 versus poorly responsive patients.