Annual change in lung function between the baseline and follow-up visit
| <10 pack-years | ≥10 pack-years | p-value | |
| Subjects | 128 | 65 | |
| ΔFEV1 mL·year–1 | −16.6 (−31.4–3.3) | −25.0 (−41.7–0.9) | 0.052 |
| ΔFEV1 % pred·year–1 | 0.40 (−0.16–1.06) | 0.08 (−0.48–0.78) | 0.022# |
| ΔFEV1/FVC·year–1 | −0.003 (−0.006–0.002) | −0.003 (−0.007–0.001) | 0.452 |
| ΔFVC mL·year–1 | −7.7 (−32.7–17.2) | −16.6 (−44.3–15.7) | 0.143 |
| ΔFVC % pred·year–1 | 0.59 (−0.09–1.28) | 0.33 (−0.08–1.15) | 0.227 |
Data are presented as n or median (interquartile range), unless otherwise stated. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity. #: statistically significant at p<0.05.