Consistency of reversibility status and clinical outcomes summary of pre-bronchodilator FEV1 at each visit
| Characteristic | Patients with COPD | GOLD II | GOLD III | GOLD IV | Smoker controls | Non-smoker controls |
| Pre-bronchodilator FEV1 (visit 1) | 1.25 (0.49) | 1.60 (0.44) | 1.04 (0.28) | 0.67 (0.15) | 3.20 (0.72) | 3.24 (0.79) |
| Pre-bronchodilator FEV1 (visit 2) | 1.27 (0.51) | 1.60 (0.48) | 1.07 (0.34) | 0.71 (0.21) | 3.15 (0.73) | 3.22 (0.77) |
| Pre-bronchodilator FEV1 (visit 3) | 1.26 (0.51) | 1.58 (0.47) | 1.06 (0.34) | 0.71 (0.22) | 3.15 (0.71) | 3.21 (0.79) |
| Pre-bronchodilator FEV1 (visit 4) | 1.25 (0.50) | 1.57 (0.47) | 1.04 (0.33) | 0.71 (0.23) | 3.13 (0.71) | 3.20 (0.78) |
| Variation between visits | 277 (195) | 322 (210) | 257 (173) | 179 (150) | 265 (170) | 276 (189) |
| OR for reversibility when below variation on test day | 2.920 (2.274 to 3.749) | 2.593 (1.883 to 3.570) | 3.593 (2.295 to 5.623) | 5.945 (1.300 to 27.189) | 2.818 (0.784 to 10.123) | >999.999 (<0.001 to >999.999) |
Data are given as mean (SD) or OR (95% CI).
COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; GOLD, Global initiative for chronic Obstructive Lung Disease.