Table 2 Baseline characteristics of participants in the cohort study

Age in years

673

12.69 (0.34)

343

12.68 (0.34)

330

SDQ Total Difficulties Score (SDQ TDS)

637

12.41 (5.76)

328

12.33 (5.67)

309

Physical activity volume (mean counts per minute (cpm))

673

508.28 (169.42)

343

465.93 (153.25)

330

Physical activity intensity (mean daily MVPA minutes)

673

55.59 (21.47)

343

49.85 (19.24)

330

Categorical variables

n

Category

All

Females

Males

n (%)

n (%)

n (%)

Gender

673

343 (51.0)

330 (49.0)

Ethnicity

673

White

629 (93.0)

320 (93.3)

309 (93.6)

Other

44 (7.0)

23 (6.7)

21 (6.4)

Family Affluence Scale (SES)

673

Low and Med (0–5)

353 (52.0)

187 (54.5)

166 (50.3)

High (6–9)

320 (48.0)

156 (45.5)

164 (49.7)

Study school

673

1

142 (21.0)

79 (23.0)

63 (19.1)

2

116 (17.0)

64 (18.7)

52 (15.8)

3

134 (20.0)

62 (18.1)

72 (21.8)

4

81 (12.0)

41 (12.0)

40 (12.1)

5

142 (21.0)

59 (17.2)

83 (25.2)

6

58 (9.0)

38 (11.1)

20 (6.1)

Intervention arm of the AHEAD trial

673

Intervention

339 (50.4)

184 (54.3)

155 (45.7)

Control

334 (49.6)

159 (47.6)

175 (52.4)

Sleep

665

Good sleep

348 (52.0)

169 (50.0)

179 (55.0)

Poor sleep

317 (48.0)

172 (50.0)

145 (45.0)

Smoking

667

Yes

115 (17.0)

71 (20.9)

44 (13.5)

No

552 (83.0)

269 (79.1)

283 (86.5)

Drinking alcohol

603

Don’t drink

29 (4.8)

11 (3.5)

18 (6.2)

Occasional

352 (58.4)

198 (63.7)

154 (52.7)

Weekly

176 (29.2)

84 (27.0)

92 (31.5)

Frequent

46 (7.6)

18 (5.8)

28 (9.6)

Number of friends

663

None

4 (0.6)

0 (0.0)

4 (1.2)

1–2

67 (10.1)

33 (9.7)

34 (10.5)

3–6

250 (37.7)

133 (39.1)

117 (36.2)

7 or more

342 (51.6)

174 (51.2)

168 (52.0)

Belonging to teams or clubs

666

Yes

321 (48.2)

135 (39.6)

186 (57.2)

No

345 (51.8)

206 (60.4)

139 (42.8)