Table 4. Intervention effects on cardiorespiratory fitness and anthropometric variables.
| Intervention | Control | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Outcome | n = | Baseline | Follow-up | Within-group change | n = | Baseline | Follow-up | Within-group change | Adjusted difference in changea | 95% CI | p-value | Conditional ICC |
| Cardiorespiratory fitness (distance, m)b | 162 | 989 (107) | 1018 (109) | 29 (57) | 297 | 1023 (114) | 1040 (19) | 17 (72) | 9.4 | -3.7–22.4 | 0.16 | NA |
| Waist circumference (cm)c | 190 | 71.6 (8.4) | 72.8 (8.4) | 1.2 (4.1) | 410 | 70.4 (8.9) | 70.5 (8.7) | 0.2 (2.9) | 0.7 | -0.7–2.1 | 0.33 | 0.13 (school) |
| BMI | 191 | 19.8 (2.9) | 20.1 (2.9) | 0.3 (0.7) | 417 | 19.3 (3.0) | 19.7 (3.1) | 0.4 (0.7) | -0.1 | -0.2–0.0 | 0.14 | NA |
Baseline, follow-up and within-group changes are unadjusted values while between-group comparisons are adjusted. Values are mean (SD) unless stated otherwise. CI: confidence interval. BMI: body mass index. NA: not applicable. On the basis of changes of >2 standard deviations, 24 participants were further excluded from the cardiorespiratory fitness results (five at intervention and 19 at control schools).
a Estimates are the unstandardized beta-coefficients (control coded as zero, intervention coded as 1) from linear mixed models with the change in outcome adjusted for baseline value of outcome, gender and grade level. If a random effect did not improve the model fit, ordinary least squares regression was used.
b Between-group difference in change is further adjusted for overweight status at baseline.
c Between-group difference in change further adjusted for school cluster as a random effect.