Table 3

Characteristics of preterm cohorts from grade B studies reporting outcome of live births

Reference		Cohort birth period		Exclusions (details in text)		Geographical cohort		Antenatal steroids		Postnatal surfactant		Age at survival	Proportion of live births surviving for each week of gestation (%)
Reference		Cohort birth period		Exclusions (details in text)		Geographical cohort		Antenatal steroids		Postnatal surfactant		Age at survival	23	24	25	26	27
Batton¹⁵	1994–1997	No	No	Yes (64%)	Yes (81%)	dis	57	74	85
Bahado-Singh¹⁶	1990–1995	Yes	No	Yes^3-150	Yes^3-150	dis	41	68	75
Doyle¹⁷	1991–1992	No	Yes	No	No	2 y	10	33	58	72	77
Gultom¹⁸	1989–1994	Yes	No	No	No	dis	5	35	57	79	85
Hack¹⁹	1990–1992	No	No	Yes (40%)	Yes (10%)	20 m	7	40	63	77	83
Katz²⁰	Jul 89–Aug 91	Yes	No	No	No	dis		45	64	72	89
Holtrop²¹	Jan 88–Dec 91	No	No	No	No	dis	19	59	59
Magowan²²	1985–1994	No	Yes	No	No	neo		21	48	60	70
Ferrara²³	1986–1990	No	No	No	Yes (50%)	dis	44	44	70	78
Philip²⁴	1982–1991	No	No	No	No	dis				65	80
Gultom¹⁸	1983–1988	Yes	No	No	No	dis	0	0	35	57	72
Johnson²⁵	1984–1986	No	Yes	No	No	dis			22	48	62
Hack²⁶	Jul 82–Jun 88	No	No	No	No	dis	8	16	53	63	72
Whyte²⁷	Jan 82–Jun 87	Yes	No	Yes^3-150	No	dis	25	47	65	74
Van Zeben²⁸	1983	No	Yes	No	No	dis		0	15	38	54
Gilstrap²⁹	Jul 79–Mar 84	Yes	No	Yes^3-150	No	dis	0	50	29	67	100
Nwaesei³⁰	1980–1982	Yes	No	Yes^3-150	No	dis	0	10	38	46	76
Kitchen³¹	Oct 80–Mar 82	No	No	No	No	8 y		10	14	42	55
Yu³²	1977–1984	No	No	No	No	1 y	7	33	25	56	72
Milligan³³	1979–1982	No	No	No	No	dis	14	39	64	76	75
Kitchen³⁴	Jan 77–Mar 82	No	No	Yes^3-150	No	dis		7	20	45	55
Herschel³⁵	1977–1980	Yes	No	Yes^3-150	No	dis		29	11	45	61
Kitchen³⁶	1977–1978	No	No	No	No	dis		9	17	50	73
					Combined estimate		18	33	50	63	72
					(95% CI)		(14–21)	(30–36)	(48–53)	(61–65)	(66–74)

↵3-150 Percentage not specified.
2 y, 2 years of age; neo, neonatal period (28 days); dis, discharge from hospital; 20 m, 20 months of age.