Table 6 Valid and non-valid accelerometer data at baseline and follow-up

Did not receive an accelerometer (not at baseline)

3 (3.1%)

3 (4.2%)

Parental consent but no child assent

3 (3.1%)

3 (12.0%)

Received an accelerometer

n = 91

n = 69

n = 22

Non-valid

No readings

2 (2.2%)

1 (1.4%)

1 (4.5%)

Less than 3 days data

13 (14.3%)

8 (11.6%)

5 (22.7%)

 ≥ 3 days data but no weekend

18 (19.8%)

13 (18.8%)

5 (22.7%)

Valid

 ≥ 3 days with weekend

58 (63.7%)

47 (68.1%)

11 (50.0%)

Follow-up

All

n = 97

Participants present at baseline

n = 91

Received accelerometer at follow-up

(n = 77)

Intervention: Received accelerometer at follow-up

(n = 62)

Control:

Received accelerometer at follow-up

(n = 15)

No assent

5 (5.2%)

1 (1.1%)

–

–

–

Not at follow-up

15 (15.5%)

15 (16.5%)

–

–

–

Received an accelerometer

77

62

15

No data file

2 (2.1%)

2 (2.2%)

2 (2.6%)

0

2 (13.3%)

Did not return accelerometer

3 (3.1%)

3 (3.3%)

3 (3.9%)

3 (4.8%)

0

Non-valid data

 No readings

18 (18.6%)

16 (17.6%)

18 (23.4%)

15 (24.2%)

3 (20.0%)

 Less than 3 days

0

0

0

0

0

 ≥ 3 days data but no weekend

13 (13.4%)

13 (14.3%)

13 (16.9%)

9 (14.5%)

4 (26.7%)

Valid

 ≥ 3 days with weekend

41 (42.3%)

41 (45.1%)

41 (53.3%)

35 (56.5%)

6 (40.0%)