Subjects without COPD (noCOPD) with maximum mid-expiratory flow (MMEF) <80% with and without progression to COPD
| NoCOPD MMEF <80% who did not develop COPD | NoCOPD MMEF <80% who developed COPD | p-value | |
| Subjects n | 107 | 28 | |
| Age years | 54.2±11.4 | 53.3±9.9 | NS |
| Smoking history pack-years | 35.9±19.6 | 36.3±14.8 | NS |
| Active smokers, n (%) | 45 (42) | 15 (53) | NS |
| mMRC score | 1.1±1.1 | 1.8±1.2 | 0.001 |
| FEV1 % pred | 90.3±12.8 | 89.5±12.4 | NS |
| FEV1/FVC % | 77.2±3.1 | 73.1±2.8 | 0.0001 |
| Decline of FEV1 per year (mL·year−1 from V1 to V3) | 24±34 | 52±23 | 0.0001 |
Data are presented as n (%) or mean±sd. p-value refers to Mann–Whitney test or χ2 test. NS: nonsignificant; mMRC: modified Medical Research Council; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity.