Behaviour change techniques in physical activity-focused interventions for young people at risk of problematic substance use: A systematic review and meta-analysis.

Aim: This systematic review investigates behaviour change techniques in interventions promoting physical activity for young people aged 12-25 years at heightened risk of problematic substance use, and the effect of these techniques on physical activity participation and substance use outcomes.

Methods: Four databases (PsycINFO, CINAHL, SPORTDiscus and Medline) were searched between November 2020 and November 2022 for randomized and non-randomized controlled studies according to inclusion criteria. Meta-analyses were calculated using weighted, standardized averages of effect sizes (Hedges' g).

Results: Twenty-eight studies were included, 14 studies in the meta-analysis (intervention n = 1328; control n = 845). Reported BCTs included behavioural instructions, social comparison and goal setting. There was a significant effect of behaviour change techniques on combined substance use outcomes, such as cravings and consumption, for interventions reporting multiple behaviour change techniques (g = -0.33, p < .001, 95% CI [-0.50,-0.16]) or one single behaviour change technique (g = -1.84, p < .001, 95% CI [-2.89,-0.8]). Limitations include unexplained variance and limited reporting of relevant behaviour change technique data in the included studies.

Conclusion: The results indicate that using behaviour change techniques in interventions that promote physical activity for young people has an effect on substance use. Further research needs to be completed comparing the impact of the number and type of behaviour change technique, and improved reporting of intervention content is required.