School-based interventions for the treatment of childhood obesity: a systematic review, meta-analysis and meta-regression of cluster randomised controlled trials.

OBJECTIVE

Schools offer an ideal setting for childhood obesity interventions due to their access to children and adolescents. This review aimed to systematically review the impact of school-based intervention for the treatment of childhood obesity.

DESIGN

Eight databases were searched from inception till 30 May 2020. A revised Cochrane risk-of-bias tool and the Grading of Recommendations, Assessment, Development and Evaluations criteria were used to evaluate the risk of bias and overall evidence. Meta-analysis and meta-regression were performed on Stata software using the random effects model. Overall effect was evaluated using Hedges' g, and heterogeneity was assessed using Cochran's Q and I2.

SETTING

Cluster randomised controlled trials (cluster-RCT) delivered in school.

PARTICIPANTS

Children and adolescents (6-18 years of age) with overweight and obesity.

RESULTS

Twelve cluster-RCT from seven countries with 1755 participants were included in the meta-analysis. School-based interventions for the treatment of childhood obesity reduced BMI and BMI z-scores with a medium effect (g = 0·52). Subgroup analyses showed greater effectiveness of brief school-based interventions and the interventions conducted in lower-middle to upper-middle economies. Meta-regression assessed the heterogeneity and the final model, with covariates of the type of economies and trial duration, accounted for 41·2 % of the variability. The overall quality of evidence was rated low because of the high risk of bias and inconsistency.

CONCLUSIONS

School-based interventions are a possible approach to provide universal healthcare for the treatment of childhood obesity, and further well-designed cluster-RCT with longer follow-up are needed. This study is registered with PROSPERO (CRD42020160735).