Fig. 2

Graphical summery of airflow, ventilation inhomogeneity and gas diffusion. The boxplots show the median values and IQR for (a): FEV₁; (b): FEV_1,/FVC ratio, (c): D_Lco and (d): LCI .*: p ≤ 0.05; **: p ≤ 0.01; ***: p ≤ 0.001 Abbreviations: BPD: bronchopulmonary dysplasia; IQR: inter quartile range; FEV₁: forced expiratory volume in 1 s; FVC: forced vital capacity; D_{Lco adj}: diffusing capacity of the lung for carbon monoxide, adjusted for haemoglobin; LCI: lung clearance index