Table 5

Adjusted ORs for outcomes at 3 years of age in period 2 versus period 1 after multiple imputations

	Total	22 weeks	23 weeks	24 weeks
	n=3318	n=454	n=1230	n=1634
Death	0.70 (0.59 to 0.83)	0.55 (0.34 to 0.91)	0.58 (0.43 to 0.77)	0.71 (0.53 to 0.94)
Death or cerebral palsy	0.65 (0.55 to 0.76)	0.49 (0.30 to 0.81)	0.49 (0.37 to 0.65)	0.72 (0.55 to 0.93)
Death or visual impairments	0.59 (0.50 to 0.69)	0.59 (0.36 to 0.97)	0.47 (0.36 to 0.62)	0.55 (0.42 to 0.71)
Death or hearing impairments	0.69 (0.58 to 0.81)	0.55 (0.34 to 0.90)	0.57 (0.43 to 0.76)	0.68 (0.52 to 0.90)
Death or DQ of KSPD<70	0.91 (0.78 to 1.06)	0.94 (0.54 to 1.63)	0.71 (0.55 to 0.94)	0.94 (0.75 to 1.19)
Death or NDI	0.83 (0.71 to 0.97)	0.99 (0.57 to 1.72)	0.64 (0.49 to 0.84)	0.86 (0.68 to 1.07)

Values are ORs (95% CIs) after adjustments by a multivariate logistic regression with the multiple imputation method. Adjusted variables were the centre, gender, multiple gestation, maternal age, caesarean delivery, antenatal steroid use, pregnancy-related hypertension, clinical chorioamnionitis, life-threatening congenital anomalies and birth weight.
DQ, developmental quotient; KSPD, Kyoto Scale of Psychological Development; NDI, neurodevelopmental impairment.