Per-protocol analyses of the effect of AFLY5 intervention on primary and secondary outcomes assessed 12 months postintervention
| Control group (reference group) | Intervention group | Main comparison between the two groups (intervention vs control) | |||||
|---|---|---|---|---|---|---|---|
| Outcome (primary/secondary) | Np | Mean (SD) or number (%) | Np | Mean (SD) or number (%) | Np | Difference in means or OR (95% CI) | p Value |
| Continuous outcomes | |||||||
| Time spent in MVPA (min/day) | 522 | 52.56 (20.67) | 356 | 54.15 (22.27) | 878 | 2.63 (−2.10 to 7.37) | 0.28 |
| Time spent in sedentary behaviour (min/day) | 522 | 461.78 (66.33) | 356 | 466.17 (70.58) | 878 | 3.67 (−8.32 to 15.66) | 0.55 |
| Servings of fruit and vegetables (number/day) | 1062 | 1.80 (1.55) | 701 | 1.91 (1.66) | 1762 | 0.05 (−0.15 to 0.25) | 0.63 |
| Time spent screen-viewing (min/day weekday) | 1062 | 148.01 (126.39) | 701 | 134.98 (120.94) | 1762 | −8.97 (−26.81 to 8.87) | 0.32 |
| Time spent screen-viewing (min/day Saturday) | 1062 | 180.52 (164.82) | 701 | 159.35 (149.97) | 1762 | −21.73 (−41.19 to −2.26) | 0.03 |
| Body mass index (z-score) | 923 | 0.03 (1.02) | 612 | −0.03 (0.98) | 1535 | 0.01 (−0.05 to 0.07) | 0.69 |
| Waist circumference (z-score) | 993 | 0.03 (1.04) | 657 | −0.04 (0.94) | 1650 | −0.03 (−0.13 to 0.06) | 0.52 |
| Servings of snacks (number per day) | 1062 | 2.11 (1.55) | 701 | 2.07 (1.48) | 1762 | −0.03 (−0.23 to 0.16) | 0.72 |
| Servings of high-fat foods (number per day) | 1062 | 0.86 (0.94) | 701 | 0.75 (1.15) | 1762 | −0.11 (−0.26 to 0.04) | 0.14 |
| Servings of high-energy drinks (number per day) | 1062 | 2.38 (1.58) | 701 | 2.22 (1.43) | 1762 | −0.18 (−0.41 to 0.5) | 0.12 |
| Binary outcomes | |||||||
| Generally overweight/obese | 923 | 194 (21.02) | 612 | 121 (19.77) | 1535 | 0.98 (0.68 to 1.41) | 0.91 |
| Centrally overweight/obese | 993 | 421 (42.40) | 657 | 272 (41.40) | 1650 | 1.06 (0.76 to 1.49) | 0.72 |
Numbers vary by outcome as indicated in the table.
Per-protocol analysis defined as teaching at least 70% (11 out of the 16) AFLY5 lessons. All participants from the intervention schools where the teacher taught fewer than 11 lessons are excluded from these analyses.
Outcomes in bold are primary outcomes (p<0.05 indicates statistical significance); all others are secondary outcomes (p<0.01 indicates statistical significance after taking account of multiple testing).
All differences in means/ORs with their 95% CI have been estimated using a multilevel model to account for clustering (non-independence) among children from the same school. Multilevel multivariable linear regression was used for effects of the intervention on continuously measured outcomes and multilevel multivariable logistic regression was used for binary outcomes.
The following baseline/school stratifying variables were included: age, gender, the baseline measure of the outcome under consideration, school involvement in other health-promoting behaviours, school area level deprivation.
In these analyses, after removal of schools that did not teach at least 11 out of 16 of the lessons, participants were only included for each outcome if they had a follow-up measurement of that outcome. For partial missing baseline data, we used an indicator variable as described by White and Thompson,21 which means for each outcome participants are included even if they do not have a baseline measurement.
MVPA, moderate to vigorous physical activity (accelerometer assessed); Np, number of participants.