Table 4.

Proportion of subjects in each group with spirometry and multiple breath wash-out measures below −1.64 z-scores

	BPD n = 26	Preterm n = 23	Asthma n = 23	Healthy controls n = 24
FEV1 z-scores	5 (19)*	0	0	0
FVC z-scores	0	1 (4.3)	0	0
FEV1/FVC z-scores	7 (27)**	1 (4.3)	1 (4.3)	0
LCI z-scores	8 (32)***	2 (8.7)	4 (17)	1 (4.6)

BPD-, preterm- and asthma-groups were compared to healthy controls. Data are presented as numbers (%). FEV₁, FVC, FEV₁/FVC: post bronchodilator measures. *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001. Abbreviations: BPD bronchopulmonary dysplasia, FEV₁ forced expiratory volume in 1 s, FVC forced vital capacity, LCI lung clearance index