Table 1 Sample characterization.

Gender (n = 969)

Male

467(48.2)

Female

502(51.8)

Age (years) (n = 969)

13–15

511(52.7)

≥16

458(47.3)

Weight (Kg) (n = 969)

57.3 ± 11.9

Height (m) (n = 969)

1.64 ± 0.11

Scholar level (n = 969)

7° grade

212 (21.9)

8° grade

192 (19.8)

9° grade

180 (18.6)

10° grade

101 (10.4)

11° grade

141 (14.6)

12° grade

143 (14.8)

Sleeping hours (n = 969)

≤6 h

22 (2.3)

[6;7] hours

322 (33.2)

[8;9] hours

576 (59.4)

≥10 h

49 (5.1)

Disability (n = 652)^a

No disability

281 (43.1)

Difficulty with 1 activity

241 (37.0)

Difficulty with 2 activities

81 (12.4)

Difficulty with 3 activities

35 (5.4)

Difficulty with 4 activities

14 (2.1)

Difficulty with 5 activities

0 (0)

Disability index ([1;5]; n = 371)

Mean ± SD

1.5 ± 0.8

Number of pain sites (n = 652)

Pain in 1 body site

284 (29.3)

Pain in 2 body sites

190 (19.6)

Pain in 3 body sites

90 (9.3)

Pain in ≥ 4 body sites

88 (9.1)

Number of pain sites ([1;9], n = 652)^a

Mean ± SD

2.1 ± 1.3

Physical activity (n = 968)

Moderate (Yes)

714 (73.7)

Vigorous (Yes)

575 (59.3)

Watching TV/DVDs (n = 969)

No

52 (5.4)

≤1 h

404 (42.0)

[2;3] hours

399 (41.5)

≥4 h

107 (11.1)

Playing (n = 969)

No

105 (10.9)

≤1 h

345 (35.9)

[2;3] hours

313 (32.5)

≥4 h

199 (20.7)

Using mobile phones (n = 969)

No

113 (11.7)

≤1 h

361 (37.5)

[2;3] hours

195 (20.3)

[4;5] hours

105 (10.9)

≥5 h

188 (19.5)

Using computers (n = 969)

No

86 (8.9)

≤1 h

375 (39.0)

[2;3] hours

311 (32.3)

≥4 h

190 (19.8)