Development of a group-based behaviour change intervention for people with severe obesity informed by the social identity approach to health.

Introduction: Interventions to support behaviour change in people living with chronic health conditions increasingly use patient groups as the mode of delivery, but these are often designed without consideration of the group processes that can shape intervention outcomes. This article outlines a new approach to designing group-based behaviour change interventions that prioritizes recipients' shared social identity as group members in facilitating the adoption of established behaviour change techniques (BCTs). The approach is illustrated through an example drawn from research focused on people living with severe obesity.

Methods: A prioritization process was undertaken in collaboration with stakeholders, including behaviour change experts, clinicians, and a former patient to develop an evidence-based, group intervention informed by the social identity approach to health. Three phases of development are reported: (1) identification of the health problem; (2) delineation of intervention mechanisms and operationalization of BCTs for group delivery and (3) intervention manualization. The fourth phase, intervention testing and optimization, is reported elsewhere.

Results: A group-based behaviour change intervention was developed, consisting of 12 group sessions and 3 one-to-one consultations. The intervention aimed to support the development of shared social identity among recipients, alongside the delivery of evidence-based BCTs, to improve the likelihood of successful intervention and health outcomes among people living with severe obesity.

Conclusions: A manualized intervention, informed by the social identity approach to health, was systematically designed with input from stakeholders. The development approach employed can inform the design of behavioural interventions in other health contexts where group-based delivery is planned.