Univariate correlation of LCI1/20th and physiological indices
| LCI1/20th | LCI1/40th | |
| LCI1/20th | 0.76** | |
| LCI1/40th | 0.76** | |
| FEV1 % predicted | −0.40** | −0.25* |
| FVC % predicted | −0.11 | −0.61 |
| FEF25–75 | −0.43 | −0.36 |
| Scond | −0.19 | −0.07 |
| Sacin | 0.22 | 0.11 |
N=80. Pearson's correlation coefficient of lung clearance index (LCI), forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), forced expiratory flow at at 25–75% of FVC (FEF25–75), and Phase III analysis of the conducting zone (Scond) and acinar zone (Sacin). *p<0.05; **p<0.01.