Table 1 Baseline characteristics

Gender (female), n (%)

6 (8)

7 (10)

Age (years), median (range)

4 (2 to 5)

4 (2 to 5)

Study centre, n (%)

 London

24 (32.43)

26 (37.68)

 Manchester

26 (35.14)

22 (31.88)

 Newcastle

24 (32.43)

21 (30.43)

Parental qualifications (at least one parent post 16), n (%)*

63 (85)

43 (62)

Parental occupation (professional/administrative), n (%)

49 (66)

42 (61)

Ethnicity (both parents white), n (%)

45 (61)

38 (55)

ADOS-G algorithm score, mean (s.d.)

19.56 (4.35)

19.38 (4.11)

Proportion of parent communications with the child that were synchronous, mean (s.d)

29.32 (12.48)

27.21 (11.18)

Total health, education and social service cost in previous six months, mean £ (s.d.)

1422 (1035)

1366 (822)