Table 2.

Median (interquartile range) characteristics of infants treated in 114 hospitals that participated in trial of quality improvement intervention for surfactant treatment of preterm infants, in the assessment year, 2001^*

	All infants		Infants born at participating hospitals		Infants transferred to participating hospital after birth
	Intervention hospitals (n=57)	Control hospitals (n=57)	Intervention hospitals (n=57)	Control hospitals (n=57)	Intervention hospitals (n=57)	Control hospitals (n=57)
No of infants treated per neonatal unit	45 (35-75)	40 (25-68)	40 (33-64)	36 (22-56)	6 (3-12)	5 (2-12)
Birth weight (mean grams)	942 (902-968)	925 (896-973)	937 (902-963)	920 (889-960)	963 (890-1063)	989 (907-1085)
Gestational age (mean weeks)	27 (26-27)	27 (26-27)	27 (26-27)	27 (26-27)	27 (26-27)	27 (26-27)
Female (%)	47 (41-51)	45 (41-51)	47 (41-51)	47 (42-53)	50 (33-63)	40 (25-50)
Maternal ethnicity (%):
Black	24 (8-40)	29 (11-50)	26 (9-40)	29 (11-50)	13 (0-50)	15 (0-68)
Hispanic	6 (2-17)	6 (3-28)	6 (2-15)	7 (2-30)	0 (0-20)	0 (0-16)
White	57 (43-70)	44 (24-68)	59 (43-72)	44 (25-68)	50 (25-86)	50 (8-92)
Asian	1 (0-4)	0 (0-3)	1 (0-4)	0 (0-3)	0 (0-0)	0 (0-0)
Other	0 (0-3)	0 (0-4)	0 (0-2)	0 (0-2)	0 (0-0)	0 (0-0)
Small for gestational age (%)	10 (6-12)	9 (7-13)	11 (6-13)	10 (7-13)	0 (0-2)	0 (0-5)
Multiple birth (%)	26 (20-35)	24 (16-31)	27 (21-33)	25 (17-33)	0 (0-24)	0 (0-20)
Given antenatal corticosteroids (%)	77 (68-85)	77 (68-86)	83 (73-89)	84 (75-91)	33 (20-50)	40 (19-65)
Delivered by caesarean section (%)	62 (54-70)	58 (49-63)	61 (54-71)	59 (50-64)	50 (23-71)	50 (29-60)
Apgar score ≤3 at 1 minute (%)	32 (25-39)	30 (24-36)	32 (24-39)	29 (21-38)	38 (25-50)	32 (17-50)

^*Characteristics reported by study arm and birth location for clusters. Each hospital is considered a cluster.