Table 3.

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)
Total No of infants treated in neonatal units	3313	2726	2911	2314	402	412
Mean (SD) birth weight (grams)	936 (258)	930 (259)	932 (258)	924 (262)	967 (257)	963 (238)
Mean (SD) gestational age (weeks)	27 (2)	27 (2)	27 (2)	27 (2)	26 (2)	27 (2)
Female (%)	47	46	47	47	47	40
Maternal ethnicity (%):
Black	30	34	30	33	28	42
Hispanic	8	17	8	16	12	17
White	56	44	57	46	52	35
Asian	4	2	4	2	4	2
Other	2	3	2	3	4	4
Small for gestational age (%)	9	10	10	11	4	6
Multiple birth (%)	27	24	28	26	18	16
Given antenatal corticosteroids (%)	75	76	80	82	39	41
Delivered by caesarean section (%)	59	58	61	59	50	51
Apgar score ≤3 at 1 minute (%)	33	30	32	29	40	34

^*Characteristics reported by study arm and birth location without regard to cluster.