School-Based Homework Interventions for Improving 24-hour Movement Behaviours in Primary School Children: A Systematic Review and Meta-Analysis.

backgroundSchool-based interventions aimed at improving physical activity (PA), sedentary behaviour (SB) and sleep (i.e., 24-hour movement behaviours) are prevalent. However, the potential use of homework as an intervention method has been largely unexamined. Our objective was to assess the effectiveness of school-based health interventions which implement homework to improve 24-hour movement behaviours in primary school-aged children, whilst examining the moderating effects of study characteristics on intervention effectiveness.

methodsWe searched CINAHL, PubMed, Scopus, SPORTDiscus, The Cochrane Library and Web of Science on 4th March 2024 using the following eligibility criteria: (1) participants were aged 5-12 years old; (2) school-based interventions that implemented homework specifically designed to improve one or more 24-hour movement behaviours; (3) randomised- or non-randomised controlled trials, or mixed methods studies where quantitative components included experimental or quasi-experimental data that could be clearly extracted; (4) device-based measured changes in individual or combined 24-hour movement behaviours, or their compositions, were reported. Data were extracted independently by two reviewers with study quality rated using the NIH quality assessment tool. Random-effects meta-analyses were processed to compute standardised mean difference (Hedges' g), with subgroup analyses, and meta-regressions also conducted.

resultsFrom 2,281 studies, 19 studies involving 13,160 participants were included for data extraction. Meta-analyses revealed significant favourable association for school-based interventions which implemented homework for sleep outcomes (g = 1.06, p < 0.0001) and SB (g = -0.20, p = 0.0034). No significant effects of the interventions compared to controls were found for PA. Meta-regressions revealed that longer intervention durations significantly improved PA (counts per minute; β = 0.14, p = 0.0241), with no significant effects found for sleep or SB. Subgroup analyses showed significant effects of intervention on SB in RCT's in both theory-based and non-theory-based studies, though differences between subgroups were not statistically significant. Effects varied between pre- and post-implementations of 24-hour movement guidelines on SB, but these differences were also not statistically significant.

conclusionThese results highlight a significant gap in school-based interventions implementing homework targeting all 24-hour movement behaviours, emphasising the need for future interventions to focus on reducing SB and improving sleep for more beneficial outcomes. REGISTRATION: PROSPERO CRD42024518271.