Table 1

Characteristics and methods of studies included in review (by date).

Study

Study quality*

Infants enrolled

Drop outs

No. of sites

Mean GA (weeks)

Mean birth weight (grams)

Group allocation

Follow-up


n

n (%)

I

C

I

C

I (n)

C (n)


IHDP

1990

4

985

72(7.3)

8

33.0

33.0

1819

1781

377

608

18 yrs

Kang

1995

2

327

82(25.1)

3

33.1g

33.1g

1938g

1938g

197

130

5 m

Saylor

1996

3

68

3(4.4)

1

28.9

30.3

1107

1231

34f

31f*

7 yrs

APIP

1998

4

328

42(12.8)

2

31.0 d P

30.0d PA

31.0d

1560 P

1331 PA

1420

116 P

106 PA

106

5 yrs

Melynk

2001

2

55

13(23.6)

1

31.4

31.6

1483

1731

26

29

6 m

Brisch

2003

2

87

11(12.6)

1

27.0

27.0

919

987

43

44

24 m

Ohgi

2004

3

23

1(4.2)

1

30.3

30.3

1273

1360

12

11

6 m

Gianni

2006

2

36

0(0)

1

28.3

27.5

892

836

18

18

36 m

Kaaresen

2006

4

146

75a

7(3.2)

1

30.2

29.9

1402

1393

72

74

75b

5 yrs

Melynk

2006

3

260

13(5.8)

2

31.3

31.4

1683

1627

147

113

2 m

Glazebrook

2007b

3

233

11(4.7)

6

28.5d

29.0d

1121

1220

112

121

24 m

Koldewijn

2009

3

176

1(0.6)

7

29.6

30.0

1242

1306

86

90

7 yrs

Newnham

2009

3

68

5(7.4)

1

31.3

33.7

1590

1619

35

33

24 m

Teti

2009

3

194

21(10.8)

4

30.6

30.0

1455

1397

99

95

4 m

Milgrom

2010

4

45

0(0)

1

27.5

27.7

981

999

22

23

0

Neu

2010

2

87

8(9.2)

5

33.1

33.4e

33.4e

1990

1880

1980

31

29e

27e*

4 m

Spittle

2010

4

120

3(2.5)

2

27.3

27.4

1029

991

61

59

24 m

Ravn

2011

4

118

0(0)

1

33.3

33.2

1935

1919

61

57

12 m


Note: *Study methodological quality was assessed by Cochrane Collaboration’s Tool [44].

GA = gestational age; I = Intervention group; C = Control or comparison group; m = months; yrs = years

Programs: APIP = Avon Premature Infant Project; IHDP = Infant Health Development Program; P = Portage intervention; PA, = Parent Advisor intervention

a Matched term controls

b Cluster RCT with washout and crossover

c Case matched by developmental risk score, then randomly allocated to groups

d Median

e Holding comparison group; e* Control group

f Early intervention group; f* Late intervention group

g Overall mean for cohort

Benzies et al. BMC Pregnancy and Childbirth 2013 13(Suppl 1):S10   doi:10.1186/1471-2393-13-S1-S10

Open Data