Table 1. Baseline characteristics of the infants included in this study and those not included, based on incomplete data for postnatal dexamethasone use and age 2 outcomes as defined.

	Sample analysed with complete data N = 412	Sample not analysed with incomplete data N = 180	Comparison of complete and incomplete samples
Characteristics	% (n) or mean (SD)	% (n) or mean (SD)	p-value
Birth weight	899 (210)	907 (193)	0.66
Gestational age	26.4 (1.3)	26.4 (1.3)	0.88
Male sex	52% (216)	52% (93)	0.87
Multiple birth	23% (96)	19% (35)	0.30
Postnatal dexamethasone Use	29% (120)	30% (52)	0.85
Oxygen dependency at 28 days	81% (335)	77% (139)	0.25
Oxygen dependency at 36 weeks PMA	58% (240)	49% (88)	0.04
Oxygen dependency at hospital discharge	23% (93)	16% (29)	0.08
Major ultrasound abnormality in neonatal period	14% (59)	13% (23)	0.63
Maternal smoking in pregnancy	25% (99)	33% (52)	0.07