Developing a theory-informed complex intervention to improve nurse–patient therapeutic engagement employing Experience-based Co-design and the Behaviour Change Wheel: an acute mental health ward case study

Objectives Our objectives were threefold: (1) describe a collaborative, theoretically driven approach to co-designing complex interventions; (2) demonstrate the implementation of this approach to share learning with others; and (3) develop a toolkit to enhance therapeutic engagement on acute mental health wards.Design and participants We describe a theory-driven approach to co-designing an intervention by adapting and integrating Experience-based Co-design (EBCD) with the Behaviour Change Wheel (BCW). Our case study was informed by the results of a systematic integrative review and guided by this integrated approach. We undertook 80 hours of non-participant observations, and semistructured interviews with 14 service users (7 of which were filmed), 2 carers and 12 clinicians from the same acute ward. The facilitated intervention co-design process involved two feedback workshops, one joint co-design workshop and seven small co-design team meetings. Data analysis comprised the identification of touchpoints and use of the BCW and behaviour change technique taxonomy to inform intervention development.Setting This study was conducted over 12 months at an acute mental health organisation in England.Results The co-designed Let’s Talk toolkit addressed four joint service user/clinician priorities for change: (1) improve communication with withdrawn people; (2) nurses to help service users help themselves; (3) nurses to feel confident when engaging with service users; (4) improving team relations and ward culture. Intervention functions included training, education, enablement, coercion and persuasion; 14 behaviour change techniques supported these functions. We detail how we implemented our integrated co-design-behaviour change approach with service users, carers and clinicians to develop a toolkit to improve nurse–patient therapeutic engagement.Conclusions Our theory-driven approach enhanced both EBCD and the BCW. It introduces a robust theoretical approach to guide intervention development within the co-design process and sets out how to meaningfully involve service users and other stakeholders when designing and implementing complex interventions