Table 5.
Subgroup analysis of physical fitness, screen time, physical activity according to school characteristics
| Outcome | n | Control group | Intervention group | Separate model per school characteristic | Full model adjusted for school characteristics | ||
|---|---|---|---|---|---|---|---|
| Mean (SD) | Mean (SD) | Difference [95% CI] a | P | Difference [95% CI] b | P | ||
| Speed shuttle run 10×5 (s) | |||||||
| School size | 1021 | <0.01c | <0.01c | ||||
| ≤695 students | 476 | 1.58 (3.59) | 1.93 (2.47) | 0.30 [−0.55-1.14] | 0.25 | 0.22 [−0.36 -0.80] | 0.24 |
| >695 students | 545 | 3.63 (3.02) | 1.85 (2.32) | −1.83 [−2.34 to −1.32] | <0.01 | −1.49 [−2.20 to −0.78] | <0.01 |
| Vertical jump (cm) | |||||||
| School gender | 1038 | 0.03c | 0.03c | ||||
| Male and female students | 698 | 0.29 (6.82) | 2.93 (6.70) | 3.55 [1.73-5.36] | <0.01 | 3.57 [1.76-5.38] | <0.01 |
| Only female students | 340 | −0.34 (5.67) | −0.30 (6.48) | 0.14 [−2.21-2.49] | 0.45 | 0.06 [−2.16-2.28] | 0.48 |
| Flamingo (trying/min) | |||||||
| Physical activity space | 571 | 0.04c | 0.04c | ||||
| ≤4.07 (students/m2) | 237 | −5.26 (7.87) | −0.82 (6.40) | 3.29 [0.97 - 5.61] | 0.01 | 3.29 [0.97 - 5.61] | 0.01 |
| >4.07 (students/m2) | 334 | −3.38 (7.38) | −2.43 (6.68) | 0.91 [−0.99 - 2.81] | 0.19 | 0.91 [−0.99 - 2.81] | 0.19 |
| % sedentary in weekends (screen time >3 h/day) | |||||||
| School type | 1071 | 0.03c | 0.05c | ||||
| Private | 438 | 0.18 (0.39) | 0.31 (0.46) | 0.13 [0.04 - 0.21] | <0.01 | 0.13 [0.03 - 0.23] | 0.01 |
| Public | 633 | 0.26 (0.44) | 0.25 (0.43) | −0.02 [−0.10 - 0.05] | 0.29 | 0.00 [−0.14 - 0.13] | 0.48 |
| Proportion of adolescents who meet the recommendation (60 min of MVPA/day) | |||||||
| School schedule | 134 | 0.01c | 0.02c | ||||
| Half-day class | 110 | 0.70 (0.46) | 0.96 (0.19) | 0.28 [0.14-0.42] | <0.01 | 0.37 [0.14 - 0.61] | 0.01 |
| Full-day class | 24 | 1.00 (0.00) | 0.77 (0.44) | −0.29 [−0.54 to −0.04] | 0.02 | −0.29 [−0.54 to −0.04] | 0.02 |
aDifferences and CI were obtained from a linear mixed model adjusted for BMI z-scores, gender, socio-economic status and physical activity knowledge at baseline, including the interaction term between school characteristic and allocation group.
bDifferences and CI were obtained from linear mixed models adjusted for BMI z-scores, gender, socio-economic status and physical activity knowledge, including the interaction term between school characteristic and allocation group. Models included all school characteristics as fixed effects that were significantly associated with the outcome (P < 0.05) and all significant interaction terms (P < 0.1) from the separate models.
cP for interaction (significant at P < 0.10).
CI: confidence interval; SD: standard deviation.