Table 1 Demographic and behavioural characteristics of those who participated at T₃ and those who declined to take part T₃

Age

Median (IQR)

12 (8)

10 (7.75)

5682

.055

Gender

% male

80.6% (54)

87% (176)

.405

.525

Ability

% partially able/able

94% (63)

90% (183)

6110

.173

Mobility

% mobile

97% (65)

97% (197)

N/A^a

1.000

Speech

% verbal

91% (61)

86% (174)

1.097

.295

Self-injury

% with behaviour

37.3% (25)

37% (76)

.004

.949

Mood total score

Median (IQR)

35 (9)

33 (10)

6472

.593

Activity total score

Median (IQR)

32 (31)

39 (32)

5475

.037*

TAQ impulsivity

Median (IQR)

15 (12)

17 (10)

5613

.046*

TAQ overactivity

Median (IQR)

14 (14)

16 (18)

5758

.076

Repetitive behaviour total score

Median (IQR)

35 (9)

28 (25)

4734

< .001*

RBQ compulsive behaviour

Median (IQR)

5 (7)

6 (11)

5462

.046*

RBQ insistence on sameness

Median (IQR)

3 (6)

4 (5)

5667

.181

RBQ restricted preferences

Median (IQR)

3 (5)

5 (5)

3988

.004*

RBQ repetitive use of language

Median (IQR)

6 (6)

6 (7)

4669

.200

Autism phenomenology total score

Median (IQR)

25 (10)

25 (11)

5462

.628