Within- and between-session variability for the controlled and free breathing protocols

Within-session CoVBetween-session difference95% LOABetween-session ICC
Controlled breathing
 FRCCB L3.0±1.9%−0.02±0.47−0.94–0.910.927
ScondCB L−1−0.003±0.009−0.021–0.0150.867
SacinCB L−1−0.002±0.02−0.039–0.0340.828
Free breathing
 FRCFB L3.9±2.4%−0.04±0.026−0.54–0.470.979
ScondFB L−10.006±0.016−0.026–0.0380.411
SacinFB L−10.003±0.054−0.103–0.1090.278

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.