Behavior change techniques associated with changes in post-intervention and maintained changes in self-efficacy for physical activity:Systematic review with meta-analysis

Background: Self-efficacy is an important determinant of physical activity but it is unclear how best to increase self-efficacy for physical activity and to maintain these changes. Purpose: This systematic review aimed to identify which specific behavior change techniques (BCTs), BCT clusters, and number of BCTs were associated with changes in post-intervention and maintained changes in self-efficacy for physical activity across all adult populations. Methods: A systematic search yielded 180 randomized trials (204 comparisons) which reported changes in self-efficacy. BCTs were coded using the BCT Taxonomy v1. Hierarchical cluster analysis explored the clustering of BCTs. Meta-analyses and moderator analyses examined whether the presence and absence of individual BCTs in interventions were associated with effect size changes for self-efficacy. Results: Small intervention effects were found for post-intervention self-efficacy for physical activity (d=0.26; 95% CI: [0.21, 0.31]; I2=75.8%). ‘Information about social, environmental, and emotional consequences’ was associated with higher effect sizes, whereas ‘social support (practical)’ was associated with lower effect sizes. Small, and non-significant effects were found for maintained changes in self-efficacy for physical activity (d=0.08; CI: [-0.05, 0.21]; I2=83.8%). Lack of meaningful clustering of BCTs was found. A significant positive relationship was found between number of BCTs and effect sizes for maintained changes in self-efficacy for physical activity. Conclusions: There does not appear to be a single effective approach to change self-efficacy for physical activity in all adults: different approaches are required for different populations. Interventions with more BCTs seem more effective at maintaining changes in self-efficacy for physical activity.