Table 3. Adjusted differences for the primary (BMI z score) and secondary outcomes between intervention and control groups at 12 months.
| Characteristics | Intervention group | Control group | MD or OR (95% CI), P value | |||
|---|---|---|---|---|---|---|
| Na | Mean (SD)/Median [IQR] / % | Na | Mean (SD)/Median [IQR] /% | Baseline adjustedb (primary analysis) | Further adjustedc (secondary analysis) | |
| Adiposity-related outcomes | ||||||
| BMI z scored | 804 | -0.35 (1.22) | 777 | -0.23 (1.34) | -0.13 (-0.26 to 0.00), p = 0.048 | -0.13 (-0.26 to -0.01), p = 0.041 |
| Obese/Overweighte | ||||||
| No | 679 | 84.5% | 631 | 81.2% | NA | NA |
| Yes | 125 | 15.5% | 146 | 18.8% | 0.53 (0.27 to 1.05), p = 0.067 | 0.65 (0.31 to 1.36), p = 0.258 |
| Waist circumference | 805 | 57.45 (6.82) | 781 | 57.85 (6.87) | -0.37 (-0.85 to 0.11), p = 0.128 | -0.53 (-1.06 to -0.01), p = 0.047 |
| Body fat %f | 476 | 18.96 (5.64) | 431 | 19.95 (5.64) | -0.01 (-0.03 to 0.01), p = 0.171 | -0.01 (-0.03 to 0.00), p = 0.136 |
| Blood pressure | ||||||
| Systolic blood pressure (mmHg) | 805 | 101.54 (8.68) | 781 | 101.33 (8.99) | -0.04 (-1.37 to 1.29), p = 0.953 | -0.24 (-1.58 to 1.10), p = 0.723 |
| Diastolic blood pressure (mmHg) | 805 | 60.82 (7.15) | 781 | 61.22 (7.18) | -0.65 (-1.97 to 0.67), p = 0.332 | -0.71 (-2.01 to 0.59), p = 0.287 |
| Behavioural outcomes | ||||||
| Daily average servings of fruit and vegetables | 787 | 3·00 [2·00–4·00] | 741 | 3·00 [2·00–4·00] | 0.33 (0.14 to 0.52), p = 0.001 | 0.34 (0.17 to 0.51), p<0.001 |
| ≥5 portions of fruit and vegetablesg | ||||||
| No | 653 | 82.1% | 696 | 90.5% | NA | NA |
| Yes | 142 | 17.9% | 73 | 9.5% | 2.00 (1.45 to 2.76), p<0.001 | 2.12 (1.47 to 3.07), p<0.001 |
| Weekly average servings of unhealthy snacks and sugar-added drinks | 770 | 1.00 [0.00–3.00] | 732 | 2.50 [0.00–3.50] | -0.81(-1.42 to -0.20), p = 0.010 | -0.76 (-1.30 to -0.22), p = 0.006 |
| Engaging in screen-based sedentary behaviour on weekdays | ||||||
| No | 310 | 38.5% | 301 | 38.4% | NA | NA |
| Yes | 496 | 61.5% | 482 | 61.6% | 1.04 (0.82 to 1.32), p = 0.748 | 0.99 (0.78 to 1.27), p = 0.953 |
| Engaging in screen-based sedentary behaviour on weekend days | ||||||
| No | 172 | 21.3% | 125 | 16.0% | NA | NA |
| Yes | 634 | 78.7% | 658 | 84.0% | 0.70 (0.52 to 0.93), p = 0.014 | 0.60 (0.44 to 0.82), p = 0.001 |
| Engaging in active sports, dance, or games at least once in previous weekend | ||||||
| No | 144 | 17.9% | 199 | 25.4% | NA | NA |
| Yes | 662 | 82.1% | 584 | 74.6% | 1.58 (1.23 to 2.04), p<0.001 | 1.47 (1.10 to 1.96), p = 0.009 |
| Objectively measured sedentary time (minutes/24 hours) | 669 | 461.97 (98.28) | 645 | 468.64 (93.01) | -8.45 (-30.69 to 13.80), p = 0.457 | -6.26 (-27.26 to 14.73), p = 0.559 |
| Parent-reported sedentary time (minutes/24 hours) | 814 | 202.74 (125.23) | 779 | 217.61 (132.87) | -12.63(-26.73 to 1.46), p = 0.079 | -14.71 (-29.54 to 0.11), p = 0.052 |
| Objectively measured MVPA time (minutes/24 hours) | 669 | 63.98 (32.52) | 645 | 62.65 (27.54) | 3.24 (-3.46 to 9.94), p = 0.343 | 0.56 (-5.32 to 6.43), p = 0.853 |
| Parent-reported MVPA time (minutes/24 hours) | 816 | 132.86 [90.00–184.29] | 779 | 126.43 [90.00–188.57] | 1.20 (-9.44 to 11.85), p = 0.825 | 0.50 (-10.64 to 11.65), p = 0.929 |
| Achieving ≥60 minutes MVPA in 24 hours (objectively measured)h | ||||||
| No | 353 | 52.8% | 337 | 52.3% | NA | NA |
| Yes | 316 | 47.2% | 308 | 47.8% | 1.16 (0.69 to 1.95), p = 0.564 | 1.02 (0.61 to 1.68), p = 0.954 |
| Achieving ≥60 minutes MVPA in 24 hours (parent reported)h | ||||||
| No | 58 | 8.2% | 58 | 8.5% | NA | NA |
| Yes | 646 | 91.8% | 622 | 91.5% | 0.97 (0.64 to 1.46), p = 0.883 | 0.78 (0.49 to 1.22), p = 0.273 |
| Psychosocial outcomes | ||||||
| PedsQL total score | 806 | 85.86 [77.17–92.39] | 783 | 83.69 [76.08–91.30] | 1.27 (-0.13 to 2.67), p = 0.076 | 1.16 (-0.36 to 2.69), p = 0.134 |
| CHU9D utility score | 806 | 0.94 (0.06) | 781 | 0.93 (0.07) | 0.008 (0.000 to 0.015), p = 0.034 | 0.007 (0.000 to 0.016), p = 0.056 |
| Kidscreen-52 bullying | 806 | 13.94 (1.64) | 783 | 13.73(1.82) | 0.136 (-0.085 to 0.359), p = 0.228 | 0.090 (-0.134 to 0.314), p = 0.431 |
aN = the total number of children from whom we collected valid data at the follow-up.
bBaseline adjusted = adjusted for baseline outcome and school clustering.
cFurther adjusted = adjusted for baseline outcome, prespecified school-level (i.e., whether the school provides midmorning snack, whether the school has an indoor activity room) and child-level sociodemographic (i.e., age, sex, and mother education level) and behavioural (daily average servings of fruit and vegetables, weekly servings of unhealthy snacks and sugar-added drink, objectively measured time in MVPA [minutes/24 hours] and objectively measured sedentary time [minutes/24 hours]) covariates.
dIntracluster correlation coefficients of the primary outcome at the follow-up were 0.118 (0.054 to 0.240) and 0.112 (0.057 to 0.211), respectively, in the baseline-adjusted and further-adjusted analyses.
eWeight status was defined according WHO growth charts (BMI z score) cut off points.
fBased on children who provided valid data.
gAdjusted for baseline daily average servings of fruit and vegetables.
hAdjusted for baseline objectively measured time in MVPA (per 24 hours).
Abbreviations: BMI, body mass index; CHU9D, Child Health Utility 9D; IQR, interquartile range; MD, mean difference; MVPA, interquartile range; OR, odds ratio; PedsQL, Pediatric Quality of Life Inventory