Table 2 Descriptive Statistics of Study measures, by gender and overall
|  | Males (n = 293) | Females (n = 350) | Overall (n = 643) |
|---|---|---|---|
Age (yrs: mean, SD) | 14.0 (0.2) | 14.0 (0.2) | 14.0 (0.2) |
SBM activity (h/wk: median, IQR) | Â | Â | Â |
Computer use: | Â | Â | Â |
General computer use | 0 (2.2) | 0.5 (2.3) | 0.2 (2.2) |
0 (0) | 0 (0.7) | 0 (0) | |
Computer-graphics | 0 (0) | 0 (0) | 0 (0) |
Internet | 0 (1.1) | 0 (1.2) | 0 (1.2) |
Word processing | 0 (0) | 0 (0) | 0 (0) |
Computer games | 1.0 (5.9) | 0 (1.8) | 0 (3.6) |
Non-computer games | 0.7 (4.5) | 0 (0) | 0 (1.3) |
TV | 17.4 (13.9) | 14.3 (12.2) | 15.7 (13.8) |
Total SBM activity^ | 30.1 (19.5) | 21.2 (13.3) | 24.8 (16.8) |
Other activities | Â | Â | Â |
Reading (h/wk: median, IQR) | 1.2 (3.0) | 1.6 (3.1) | 1.4 (3.1) |
Phone use (h/wk: median, IQR) | 0 (0.2) | 0.3 (1.3) | 0 (0.9) |
Pedometer count (steps/wk: mean, SD) | 78,854 (28,452) | 68,435 (23,127) | 73,149 (26,169) |
Moderate/Vigorous activity (h/wk: mean, SD) | 15.7 (8.4) | 13.1 (6.9) | 14.3 (7.7) |
Physical measures | Â | Â | Â |
Body mass index (mean, SD) | 20.6 (3.7) | 21.4 (4.2) | 21.0 (4.0) |
Back muscle endurance (secs: mean, SD) | 87.0 (61.3) | 90.0 (65.3) | 88.5 (63.5) |
Sitting trunk angle (deg: mean, SD) | 238.0 (11.8) | 225.6 (10.3) | 231.4 (12.6) |
Spinal pain | Â | Â | Â |
Neck pain sitting (%) | 14/291 (4.8%) | 31/348 (8.9%) | 45/639 (7.0%) |
Back pain sitting (%) | 31/291 (10.7%) | 62/350 (17.7%) | 93/641 (17.7%) |
Psychosocial measures | Â | Â | Â |
Self-efficacy1 (mean, SD) | 3.4 (0.6) | 3.3 (0.6) | 3.4 (0.6) |
Depression2 (median, IQR) | 3.0 (7.0) | 5.0 (8.0) | 4.0 (7.0) |
Internalising behaviour3 (mean, SD) | 9.0 (6.1) | 10.2 (6.5) | 9.7 (6.4) |
Externalising behaviour3 (mean, SD) | 10.1 (6.1) | 10.3 (6.2) | 10.2 (6.2) |
Socioeconomic Status based on CD4 (mean, SD) | 1042 (91) | 1036 (91) | 1038 (91) |