Efficacy of theory-based interventions for young people with type 1 diabetes: a systematic review and meta-analysis.

Purpose: Theory-based behaviour change interventions have been recommended to improve outcomes for young people with type 1 diabetes. However, theory has exclusively been considered in a simplistic all-or-none fashion. We therefore (1) examined the nature and extent of explicit theory use in published interventions involving young people with type 1 diabetes and (2) the relationship between how theory is used and intervention outcomes.