Table 2 Characteristics of the experimental and control groups

Background information

 Number of boys^a

40 (58 %)

30 (57 %)

0.880

 Average age^b

11.4 (6.3)

12.2 (5.5)

0.431

 Born in the Netherlands^a

69 (96 %)

51 (96 %)

0.477

 Mother born in the Netherlands^a

64 (90 %)

49 (93 %)

0.746

 Father born in the Netherlands^a

64 (90 %)

48 (91 %)

0.694

 No parent with ID^a

23 (32 %)

21 (39 %)

0.317

 One parent with ID^a

20 (28 %)

18 (34 %)

 Both parents with ID^a

28 (39 %)

14 (26 %)

Prior history

 Number of years the child has received care^b

5.5 (4.2)

6.6 (3.9)

0.127

 Number of years the family has received care^b

5.5 (4.8)

6.2 (4.7)

0.447

 Number of years the parent(s) have received care^b

7.8 (5.9)

8.0 (4.9)

0.775

 Neglect^a

20 (28 %)

13 (24 %)

0.650

 Sexual abuse^a

5 (7 %)

5 (9 %)

0.694

 Physical abuse^a

7 (10 %)

8 (15 %)

0.376

 Family conflict^a

27 (38 %)

22 (41 %)

0.695

 Divorced parents^a

25 (35 %)

22 (41 %)

0.475

Areas of concern

 Child functioning^b

3.4 (2.0)

3.2 (1.8)

0.645

 Developmental delay^a

45 (63 %)

39 (74 %)

0.229

 Social and emotional problems^a

39 (55 %)

33 (62 %)

0.413

 Oppositional defiant disorder^a

24 (34 %)

12 (23 %)

0.176

 Attachment problems^a

18 (25 %)

12 (23 %)

0.727

 Aggressive behaviour^a

13 (18 %)

7 (13 %)

0.445

Family/child-rearing environment^b

4,0 (2,2)

3,9 (2,3)

0.718

 Parent(s) with ID^a

46 (65 %)

28 (53 %)

0.317

 Lack of parenting skills^a

42 (59 %)

24 (45 %)

0.126

 Family conflict^a

29 (41 %)

14 (26 %)

0.095

 Mental health problems of parent(s)^a

17 (24 %)

15 (28 %)

0.842

 Lack of understanding of problems^a

14 (20 %)

16 (30 %)

0.178

Wider environment^b

1.5 (1.3)

1.1 (1.2)

0.130

 Financial problems^a

20 (28 %)

20 (38 %)

0.260

 Problems in the residential environment^a

20 (28 %)

8 (15 %)

0.085

 Lack of social netwerk^a

10 (14 %)

4 (8 %)

0.255