Within- and between-session variability for the controlled and free breathing protocols
| Within-session CoV | Between-session difference | 95% LOA | Between-session ICC | |
| Controlled breathing | ||||
| FRCCB L | 3.0±1.9% | −0.02±0.47 | −0.94–0.91 | 0.927 |
| LCICB | 2.4±1.7% | 0.13±0.34 | −0.53±0.79 | 0.849 |
| ScondCB L−1 | −0.003±0.009 | −0.021–0.015 | 0.867 | |
| SacinCB L−1 | −0.002±0.02 | −0.039–0.034 | 0.828 | |
| Free breathing | ||||
| FRCFB L | 3.9±2.4% | −0.04±0.026 | −0.54–0.47 | 0.979 |
| LCIFB | 3.1±2.2% | 0.15±0.51 | −0.84–1.14 | 0.704 |
| ScondFB L−1 | 0.006±0.016 | −0.026–0.038 | 0.411 | |
| SacinFB L−1 | 0.003±0.054 | −0.103–0.109 | 0.278 | |
Data are presented as mean±sd unless otherwise stated. Mean differences are Visit 2 minus Visit 1. CoV: coefficient of variation; 95% LOA: 95% limits of agreement; ICC: intra-class correlation coefficient; FRC: functional residual capacity; LCI: lung clearance index; Scond: conducting airways ventilation heterogeneity; Sacin: distal/intra-acinar airways ventilation heterogeneity.