Identifying effective behavior change techniques in interventions for enhancing the implementation of school-based policies and/or practices to prevent chronic disease in students: a secondary analysis of a systematic review

School-based interventions improve healthy eating, physical activity, and reduce tobacco, and/or alcohol use in students. While strategies supporting their implementation have been found effective, a comprehensive understanding of the active ingredients [e.g. behavior change techniques (BCTs)] remains unclear.

To describe and examine which BCTs within implementation strategies are associated with increased implementation of school-based interventions targeting healthy eating, physical activity, tobacco, and/or alcohol use in students aged 5-18.

A secondary analysis was conducted on 39 randomized controlled trials (RCTs) from a 2024 Cochrane review. Individual BCTs within implementation strategies were coded using the BCT taxonomy v1 and mapped to the Behavior Change Technique Ontology (BCTO). Mode of delivery, setting, and source were coded. Meta-regressions using random-effect models assessed the associations between identified BCTs (at the highest level of aggregation of the BCTO) and effective implementation of policies and/or practice (e.g. number of curriculum lessons taught).

Eighty-four independent BCTs were identified and meta-regression analysis revealed that out of 14 highest level of aggregation BCTs, "Associative learning" (e.g. Prompt intended action) had a statistically significant association with increased implementation (standard mean difference 0.90, 95% confidence interval 0.08, 1.72; 30 trials), which were primarily delivered face to face and by teachers or researchers.

Our findings suggest that "Associative learning BCTs" should be prioritized in future school-based interventions to address implementation barriers and increase implementation of policies and/or practices. Opportunities remain to operationalize and evaluate underrepresented BCTs amenable to school settings in future implementation studies.