Mechanisms of action in group interventions study: framework for designing and delivering group-based health interventions

Abstract

Background: Groups are commonly used to support and promote health-related behaviour change. Considerable research has been devoted to exploring intra-personal processes underpinning behaviour change but group-specific, inter-personal change mechanisms remain poorly understood. This study aimed to develop a framework of change processes in group-based health interventions, and identify examples of these processes, and practical strategies used to facilitate them, in group-based weight-loss programmes. Methods: A conceptual framework was developed through: (1) review of literature, including theories of group processes, taxonomies of behaviour change techniques, qualitative studies, and assessment tools relevant to group interventions; (2) consultations with, and feedback from, researchers, group participants and facilitators; and (3) coding of intervention manuals and 38 transcripts of group sessions (sampled for diversity) from 3 studies of group-based weight-loss interventions. Examples of change processes and facilitation strategies were identified through qualitative analysis of the 38 transcripts. Findings: Key concepts and processes in group-based health interventions were synthesised into a conceptual framework, and categorised into (1) group dynamic and development processes, (2) inter-personal change processes, and (3) intra-personal change processes. Practical strategies relevant to (1) group design, (2) group set-up, (3) group facilitation, and (4) group closure were identified. Discussion: The framework integrates a large and diverse literature on change processes in groups, and provides a practical tool for researchers and practitioners working with group-based health interventions. The framework, and identified practical strategies, can be used to design and deliver better group-based health interventions, support training of group facilitators and guide evaluations of group-based interventions.