Mean baseline anthropometric and blood pressure outcomes (±SD), modelled changes (95% CI) from baseline for each group, interaction p value and the main effects (95% CI) at 18 and 30 months
| Outcome | N | Control group | n | PA-I group | n | SB-I group | n | PA+SB I group | PA×SB interaction (P value) | Main effects (if interaction not significant) or intervention effects (comparison between each experimental group and the control group) if interaction significant | ||
| PA intervention | SB intervention | PA+SB intervention | ||||||||||
| Body mass index z-score | ||||||||||||
| Baseline | 141 | 0.44±1.06 | 153 | 0.32±1.03 | 120 | 0.32±0.89 | 150 | 0.41±0.94 | ||||
| Change at 18 months | 126 | 0.01 (−0.06 to 0.08) | 135 | −0.02 (−0.09 to 0.05) | 112 | −0.05 (−0.13 to 0.03) | 130 | 0.04 (−0.04 to 0.11) | p=0.128 | 0.03 (−0.05 to 0.10) | −0.001 (−0.08 to 0.07) | NA |
| Change at 30 months | 114 | 0.01 (−0.06 to 0.09) | 118 | −0.12** (−0.20 to –0.05) | 94 | −0.13** (−0.22 to –0.05) | 98 | −0.04 (−0.12 to 0.04) | 0.22** (0.08 to 0.38) | −0.13* (−0.24 to –0.03) | −0.14* (−0.26 to –0.03) | −0.05 (−0.16 to 0.06) |
| Waist circumference (cm) | ||||||||||||
| Baseline | 141 | 59.9±7.9 | 153 | 59.7±7.4 | 120 | 59.6±6.0 | 150 | 60.5±7.0 | ||||
| Change at 18 months | 128 | 3.76*** (2.80 to 4.72) | 135 | 3.32*** (2.54 to 4.10) | 112 | 2.29c (1.26 to 3.32) | 130 | 2.61*** (1.64 to 3.54) | p=0.519 | −0.09 (−1.03 to 0.84) | −1.04* (−1.97 to –0.10) | NA |
| Change at 30 months | 115 | 5.95*** (4.94 to 6.95) | 118 | 5.06*** (4.08 to 6.05) | 94 | 3.71*** (2.65 to 4.76) | 98 | 3.94*** (2.94 to 4.94) | −0.35 (−1.36 to 0.66) | −1.65** (−2.66 to –0.65) | NA | |
| Systolic blood pressure (mm Hg) | ||||||||||||
| Baseline | 132 | 102.5±9.0 | 149 | 100.3±8.8 | 116 | 100.0±7.7 | 140 | 103.6±9.2 | ||||
| Change at 18 months | 121 | 3.49*** (1.57 to 5.41) | 134 | 4.79*** (3.11 to 6.48) | 108 | 4.95*** (2.89 to 7.01) | 121 | 0.04 (−1.88 to 1.96) | −6.21** (−9.91 to –2.40) | 1.30 (−1.25 to 3.85) | 1.46 (−1.36 to 4.27) | −3.45* (−6.16 to –0.73) |
| Change at 30 months | 108 | −0.44 (−2.42 to 1.55) | 115 | 1.80 (−0.14 to 3.74) | 90 | −0.58 (−2.71 to 1.56) | 91 | −2.96** (−2.89 to –0.94) | −4.62* (−8.58 to –0.61) | 2.24 (−0.54 to 5.01) | −0.14 (−3.06 to 2.77) | −2.52 (−5.35 to 0.31) |
| Diastolic blood pressure (mm Hg) | ||||||||||||
| Baseline | 132 | 61.8±9.3 | 149 | 58.8±8.0 | 116 | 59.2±7.9 | 140 | 61.9±8.1 | ||||
| Change at 18 months | 121 | 0.60 (−1.41 to 2.60) | 134 | 4.24*** (2.58 to 5.90) | 108 | 3.11** (0.97 to 5.24) | 121 | −2.19* (−4.19 to –0.20) | −8.94*** (−12.77 to –5.01) | 3.64** (1.04 to 2.25) | 2.51 (−4.42 to 5.44) | −2.79 (−5.62 to 0.04) |
| Change at 30 months | 108 | −1.56 (−3.63 to 0.52) | 115 | 0.96 (−1.05 to 2.97) | 90 | −1.12 (−3.33 to 1.08) | 91 | −4.23* (−6.28 to –2.17) | −5.62** (−9.70 to –1.46) | 2.52 (−0.37 to 5.40) | 0.43 (−2.59 to 3.46) | −2.67 (−5.59 to 0.25) |
Significant intervention effects bolded. All estimates of group-specific changes from baseline and intervention effects are adjusted for school socioeconomic status, child’s age and sex, and baseline outcome value. If the interaction of PA and SB interventions was not significant, only main effects are reported. These represent the adjusted average difference in change from baseline between participants receiving the PA or SB intervention and those not receiving the interventions. If the interaction of PA and SB interventions was significant, intervention effects reported in this table represent the adjusted average difference in change from baseline between participants in a particular intervention group (PA-I, SB-I or PA+SB-I) and the control group. Only main effects of PA and SB are reported because the interaction effect of PA and SB interventions was not significant. *p<.05; **p<.01; ***p<.001.
PA+SB I, combination of PA-I and SB-I.; n, number of observations at specific time points; NA, not applicable; PA-I, physical activity (PA) promotion group; SB-I, reducing sedentary behaviour (SB) group.