Table 2. Adjusted changes in anthropometric and PA/SB-related variables from baseline to the trial period and the post-trial follow-up.
| Variable | Intra-cluster correlations | Group | Baseline valuesa | Changes after 2 years of triala | Changes at the end of the triala | Changes at the post-trial follow-upa | P intervention | P interaction intervention-by-time |
|---|---|---|---|---|---|---|---|---|
| Excess body mass index (kg m−2) | 0.035 | Intervention | 1.61 | +0.10 (−0.10 to 0.29) | +0.10 (−0.10 to 0.29) | +0.01 (−0.20 to 0.23) | ||
| Control | +0.44 (0.24 to 0.63) | +0.41 (0.22 to 0.61) | +0.34 (0.12 to 0.56) | |||||
| Difference Intervention-Control | −0.34 (−0.62 to 0.05) | −0.32 (−0.60 to 0.03) | −0.32 (−0.64 to 0.01) | <0.01 | 0.99 | |||
| z-Body mass index (kg m−2) | 0.020 | Intervention | 0.60 | −0.03 (−0.10 to 0.05) | −0.08 (−0.16 to −0.01) | −0.14 (−0.23 to −0.06) | ||
| Control | +0.09 (0.02 to 0.16) | +0.03 (−0.04 to 0.10) | −0.03 (−0.12 to 0.05) | |||||
| Difference Intervention-Control | −0.11 (−0.22 to −0.01) | −0.11 (−0.22 to −0.01) | −0.11 (−0.22 to 0.00) | 0.02 | 0.99 | |||
| Body mass index (kg m−2) | 0.039 | Intervention | 18.64 | +1.12 (0.92 to 1.31) | +2.44 (2.25 to 2.63) | +3.54 (3.33 to 3.76) | ||
| Control | +1.45 (1.25 to 1.65) | +2.71 (2.51 to 2.90) | +3.87 (3.65 to 4.09) | |||||
| Difference Intervention-Control | −0.33 (−0.61 to 0.05) | −0.27 (−0.55 to 0.01) | −0.33 (−0.64 to 0.02) | <0.01 | 0.90 | |||
| Fat mass index (kg m−2) | 0.016 | Intervention | 3.65 | +0.23 (0.06 to 0.40) | +0.81 (0.64 to 0.97) | +0.76 (0.57 to 0.94) | ||
| Control | +0.58 (0.41 to 0.75) | +0.92 (0.75 to 1.09) | +0.93 (0.73 to 1.12) | |||||
| Difference intervention-control | −0.35 (−0.59 to 0.11) | −0.11 (−0.35 to 0.13) | −0.17 (−0.44 to 0.10) | 0.03 | 0.02 | |||
| LPAT (h per week) | 0.016 | Intervention | 2.59 | +0.67 (0.28 to 1.07) | +0.90 (0.50 to 1.29) | −0.32 (−0.75 to 0.11) | ||
| Control | +0.19 (−0.21 to 0.59) | −0.05 (−0.45 to 0.35) | −0.74 (−1.19 to 0.29) | |||||
| Difference Intervention-Control | +0.48 (−0.08 to 1.05) | +0.94 (0.38 to 1.51) | +0.42 (−0.21 to 1.04) | <0.001 | 0.03 | |||
| Regular LPA > 30 min per week (%) | 0.084 | Intervention | 60.0 | +30.6 (27.4 to 33.0) | +28.3 (24.8 to 31.1) | −14.4 (−20.6 to 8.1) | ||
| Control | +2.7 (−3.1 to 8.1) | −4.5 (−10.4 to 1.2) | −26.5 (−32.3 to −20.3) | |||||
| OR (95% CI) intervention vs control | 6.0 (3.9 to 9.1) | 6.3 (4.2 to 9.4) | 1.7 (1.2 to 2.4) | <0.001 | <0.001 | |||
| TVT (min per day) | 0.056 | Intervention | 106.2 | −3.3 (−13.9 to 7.3) | −19.9 (−30.4 to −9.3) | −14.0 (−25.3 to −2.8) | ||
| Control | +12.0 (1.2 to 22.8) | −4.7 (−15.5 to 6.1) | +13.6 (1.7 to 25.4) | |||||
| Difference intervention-control | −15.3 (−30.5 to −0.2) | −15.2 (−30.3 to 0.01) | −27.6 (−44.0 to −11.3) | 0.02 | 0.06 | |||
| Active commuting home/schoolb (%) | 0.150 | Intervention | 32.0 | +8.2 (2.7 to 13.9) | +20.7 (15.0 to 26.4) | +11.7 (5.5 to 18.1) | ||
| Control | +1.8 (−3.7 to 7.9) | +15.7 (9.6 to 21.9) | −4.8 (−10.8 to 2.0) | |||||
| OR (95% CI) intervention vs control | 1.3 (0.9 to 1.9) | 1.2 (0.9 to 1.7) | 2.1 (1.4 to 3.5) | <0.001 | 0.09 |
Abbreviations: CI, confidence interval; LPA, leisure physical activity; LPAT, LPA time; OR, odds ratio; PA, physical activity; SB, sedentary behavior; TVT, TV/video time.
Values are adjusted means (95% CI).
>20 min. Changes are calculated with reference to baseline values. Excess BMI was calculated by subtracting the gender–age-specific median BMI of the French reference curves from BMI. Analyses were done by using mixed linear models taking into account the cluster randomization and the repeated individual data over time, with different baseline covariables as fixed effects. The intervention effect represents the global effect of the intervention over time, whereas the intervention-by-time interaction evaluates whether the intervention effect is changing over time, (that is, non-significant result indicates that the effect was maintained at the same level at the post-trial follow-up).