Skip to main content

Table 1 Frequency characteristics of the study population

From: Early predictors of behavioural problems in pre-schoolers – a longitudinal study of constitutional and environmental main and interaction effects

Variable

N (%)

M/SD or Median/Range

Independent Variables

  

BDNF Val66Met

1106

 

 Val/Val

722 (65 %)

 

 Val/Met

345 (31 %)

 

 Met/Met

39 (4 %)

 

5-HTTLPR

1015

 

 l/l

318 (31 %)

 

 l/s

473 (47 %)

 

 s/s

224 (22 %)

 

Apgar 5 min (Median/Range)

1079

10/0–10

 Low <7

12 (1 %)

 

Birthweight (Mean/SD)

1081

3554.01/540.80

 Low <2500 g

33 (3 %)

 

 Very low <1500 g

1 (0 %)

 

Gestational length (Median/Range)

1086

40/31–43

 Preterm <37 weeks

50 (5 %)

 

 Very preterm <32 weeks

2 (0 %)

 

Small for gestational age

1051

 

 Yes

21 (2 %)

 

Smoking during pregnancy

1106

 

 Yes

172 (16 %)

 

Neonatal illness

1106

 

 Yes

97 (9 %)

 

Non-optimal pregnancy/birth

1106

 

 Yes

287 (26 %)

 

EPDS (Median/Range)

1097

4/0–21

  ≥ 10

121 (11 %)

 

Life events (Median/Range)

980

4/0–18

  ≥ 90th percentile

62 (6 %)

 

LSS (Median/Range)

1106

4/0–19

  ≥ 90th percentile

79 (7 %)

 

Parental unemployment

930

 

 One or both parents unemployed

109 (12 %)

 

Sex

1106

 

 Boys

562 (51 %)

 

Parental immigration status

1106

 

 Children of immigrants

127 (11 %)

 

Dependent Variables

  

CBCL Internalizing

983

 

  ≥ 90th percentile

83 (8 %)

 

CBCL Anxious Depressed

983

 

  ≥ 90th percentile

52 (5 %)

 

CBCL Withdrawn

983

 

  ≥ 90th percentile

57 (6 %)

 

CBCL Externalizing

983

 

  ≥ 90th percentile

85 (9 %)

 

CBCL Aggressive

983

 

  ≥ 90th percentile

75 (8 %)

 

CBCL Destructive

983

 

  ≥ 90th percentile

84 (9 %)

 
  1. BDNF brain derived neurotrophic factor, 5-HTTLPR serotonin transporter gene-linked polymorphic region, EPDS Edinburgh postnatal depression scale, LSS life stress score, CBCL child behaviour checklist