Abstract
BACKGROUND: Clinical research investigating effective intervention strategies for adolescents to improve health behaviors has shifted to the application of motivational interviewing (MI). Evidence indicates that MI is an effective intervention for improving health behaviors as related to diet, exercise, and diabetes among adolescents. However, there is a lack of understanding about the mechanisms through which MI works and the contextual factors impacting MI effectiveness. The purpose of this review was to understand how, for whom, and under what circumstances MI works for adolescent health behavior change, which will inform future implementation of this intervention. To provide this in-depth understanding, a realist-informed systematic review was conducted in order to synthesize the evidence on the use of MI for health behaviors. Self-determination theory (SDT) was chosen as the candidate theory for testing in the present review. METHODS: Databases including PsycINFO, Healthstar, Cochrane, and PubMed were searched for articles published until March 2017. The search strategy included studies that examined or reviewed the effectiveness or efficacy of MI to change health behaviors among adolescent populations. The search identified 185 abstracts, of which 28 were included in the review. The literature was synthesized qualitatively (immersion/crystallization) and tested SDT as the candidate theory. RESULTS: Based on SDT, three mechanisms were found within reviewed studies, including competence, relatedness, and autonomy. The following contexts were found to impact mechanisms: school setting, clinician MI proficiency, parental involvement, and peer involvement. CONCLUSIONS: This realist-informed systematic review provides advances in understanding the mechanisms involved in MI for adolescent health behavior change. Additionally, it provides important practical information as to which contexts create the conditions for these mechanisms to occur, leading to health behavior change. The results can inform future MI interventions for adolescent health behavior change. Future research should continue to test this realist theory and also examine mechanism variables not extensively documented in order to improve our understanding of MI in this population.