Table 4.
Group differences and mean changes in fitness, screen time, physical activity and BMI after intervention
| Outcomes | Differences at individual level | Unadjusted effects at individual level c | Adjusted effects at individual level e | Effects in the pairs g | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n a (cluster) | Δ I (SD) b | Δ C (SD) b | Beta | P d | Beta | P f | ICC | 95% CI | Effect size h | 95% CI | I 2 | |
| Physical fitness | ||||||||||||
| Cardiopulmonary fitness | ||||||||||||
| 20 m shuttle run (min) | 1003 (20) | −0.17(0.83) | −0.02(1.19) | −0.18 | 0.18 | −0.19 | 0.16 | 0.15 | [−0.54 – 0.16] | −0.19 | [−0.52 – 0.14] | 89.3 |
| Speed-agility | ||||||||||||
| Speed shuttle run (s)i | 1021 (20) | 1.89 (2.09) | 2.69 (3.44) | −0.72 | 0.06 | −0.76 | 0.05 | 0.15 | [−1.58 - 0.07] | −0.81 | [−1.67 - 0.04] | 83.8 |
| Plate tapping (s)i | 1043 (20) | −0.18 (2.39) | 0.36 (2.64) | −0.61 | 0.13 | −0.70 | 0.10 | 0.32 | [−1.70 - 0.31] | −0.64 | [−1.56 - 0.34] | 93.3 |
| Flexibility | ||||||||||||
| Sit and reach (cm) | 1040 (20) | 1.84 (4.93) | 1.97 (4.61) | −0.13 | 0.37 | 0.11 | 0.39 | 0.06 | [−0.64 - 0.86] | −0.13 | [−0.96 - 0.71] | 52.7 |
| Muscle strength and endurance | ||||||||||||
| Sit-up (number/30 s) | 1031(20) | 2.45 (3.81) | 2.52 (4.15) | −0.04 | 0.47 | 0.15 | 0.36 | 0.11 | [−0.63 - 0.92] | −0.002 | [−0.95 - 0.94] | 76.3 |
| Vertical jump (cm) | 1038 (20) | 1.94 (6.80) | 0.07 (6.45) | 1.83 | 0.03 | 2.51 | 0.01 | 0.12 | [0.78 - 4.23] | 1.74 | [0.12 - 3.36] | 77.6 |
| Bent arm hang (s) | 1019 (20) | −0.64 (7.72) | 0.005(7.38) | −0.70 | 0.27 | −0.11 | 0.45 | 0.03 | [−1.67 – 1.45] | −0.68 | [−2.63 – 1.27] | 82.8 |
| Handgrip (kgf) | 1032 (20) | 5.86 (5.42) | 5.70 (6.3) | −0.03 | 0.48 | 0.59 | 0.12 | 0.06 | [−0.32 - 1.50] | 0.076 | [−1.49 - 1.34] | 81.3 |
| Balance | ||||||||||||
| Flamingo (trying/min)i | 571 (20) | −1.69 (6.60) | −4.08 (7.60) | 2.36 | 0.01 | 1.83 | 0.02 | 0.07 | [0.25 - 3.41] | 2.34 | [0.53 - 4.14] | 59.1 |
| % able to do the flamingo test | 1034 (20) | 5.15 | 5.49 | -0.05 | 0.08 | −0.37 | 0.13 | 0.03 | [−0.10 – 0.02] | −0.52 | [−0.12 – 0.02] | 38.3 |
| Screen time | ||||||||||||
| Screen time in week day (h/day) | 1071 (20) | 2.02 (3.22) | 1.83 (2.83) | 0.20 | 0.17 | 0.29 | 0.11 | 0.01 | [−0.15 - 0.73] | 0.2 | [−0.28 - 0.68] | 48.1 |
| Screen time in weekends (h/day) | 1071 (20) | 2.00 (3.66) | 2.24 (3.85) | −0.23 | 0.27 | −0.24 | 0.26 | 0 | [−0.93 - 0.45] | −0.2 | [−0.96 - 0.55] | 64.2 |
| % sedentary in week (screen time >3 h/day) | 1071 (20) | 2.57% | 11.16% | −0.05 | 0.07 | −0.06 | 0.06 | 0.01 | [−0.12 - 0 .01] | −0.05 | [−0.11 - 0.01] | 0.0 |
| % sedentary in weekends (screen time >3 h/day) | 1071 (20) | −23.57% | −27.46% | 0.05 | 0.07 | 0.04 | 0.08 | 0 | [−0.10 - 0 .01] | 0.05 | [−0.03 - 0.13] | 58.9 |
| Accelerometer data | ||||||||||||
| Total PA (counts/day) | 134 (18) | −17503 (143300) | −26291 (146553) | 22356j | 0.22 | 27804j | 0.18 | 0 | [−29525 - 85135] | 37000 | [−44000 - 120000] | 61.3 |
| Total PA (CPM/day) | 134 (18) | −6.7 (156.2) | −15.3 (183.6) | 18.8j | 0.30 | 30.2j | 0.23 | 0 | [−46.2 -106.6] | 47.8 | [−42.5 - 138.1] | 64.1 |
| Sedentary time (min/day) | 134 (18) | 26.3 (149.6) | 44.1 (158.9) | −14.4j | 0.21 | −18.1j | 0.15 | 0 | [−50.8 - 14.6] | −14.0 | [−78.9 - 50.8] | 42.8 |
| Light PA (min/day) | 134 (18) | −47.9 (69.2) | −47.1 (70.3) | 4.3j | 0.32 | 4.6j | 0.32 | 0 | [−14.6 - 23.8] | −6.1 | [−42.8 - 30.6] | 63.7 |
| MVPA (min/day) | 134 (18) | −8.8 (54.0) | −14.7 (55.1) | 10.4j | 0.17 | 13.6j | 0.08 | 0 | [−4.1- 30.8] | 15.7 | [−14.1 - 45.4] | 59.1 |
| % who meet the PA recommendation (60 min MVPA/day) | 134 (18) | −5.87% | −18.09% | 0.16 | <0.01 | 0.20 | <0.01 | 0 | [0.07 - 0.33] | 0.06k | [−0.41 - 0.53]k | 58.1k |
| Anthropometry | ||||||||||||
| Body mass index (z-score) | 1062 (20) | −0.09 (0.58) | −0.09 (0.52) | 0.02 | 0.34 | −0.01 | 0.38 | 0.02 | [−0.09 - 0.06] | −0.004 | [−0.09 - 0.08] | 41.1 |
| Overweight prevalence (%)m | 1062 (20) | −0.56 | −1.62 | 0.03 | 0.15 | 0.02 | 0.31 | 0 | [−0.05 - 0.08] | 0.03 | [−0.03 - 0.09] | 32.5 |
aTotal number of students (clusters).
bStandard deviation adjusted for clustering.
cCrude models without covariates and adjusted for clustering.
dP-value for crude models.
eAdjusted for clustering.
fMultilevel random effect models adjusted for BMI z-score, gender, socio-economic status and the physical activity knowledge at baseline. P-values were calculated with t distribution with 9 degree of freedom.
gRandom effect meta-analysis with pairs as random effect.
hPooled unstandardized mean differences.
iLower scores indicated better fitness.
jModels were adjusted for total time registered at baseline and at follow-up.
kThe results were obtained from only two pairs. In all other pairs, at least one school had all students meeting the recommendation on MVPA.
mOverweight and obese combined.
Δ I: mean difference of the outcomes measured before and after the intervention in the intervention group; Δ C: mean difference of the outcomes measured before and after the intervention in the control group; CPM: counts per minute; ICC: intraclass correlation; I2: heterogeneity; PA: physical activity, MVPA: moderate to vigorous PA.