A theory and evidence-based co-design approach to develop a supported self-management intervention for people with severe mental illness and type 2 diabetes (Preprint)

Abstract

Type 2 diabetes is 2-3 times more common among people with severe mental illness (SMI). Self-management is crucial, with additional challenges faced by people with SMI. Therefore, it is essential that any diabetes self-management programme for people with SMI addresses the unique needs of people living with both conditions, and the inequalities they experience within healthcare services.

We combined theory, empirical evidence, and co-design approaches to develop a type 2 diabetes self-management intervention for people with SMI.

The development process encompassed four steps: Step 1 involved prioritising the Mechanisms of Action (MoAs) and Behaviour Change Techniques (BCTs) for the intervention. Using findings from primary qualitative research and systematic reviews we selected candidate MoAs to target in the intervention, and candidate BCTs to use. Expert stakeholders then ranked these MoAs and BCTs in a two-phase survey. Average scores were used to generate a prioritised list of MoAs and BCTs. During step 2 we presented the survey results to an expert consensus workshop to agree the definitive list of MoAs and BCTs for the intervention and identify potential modes of delivery. Step 3 involved developing trigger films using evidence from step 1 and step 2. We employed animations to present the experiences of people with SMI managing diabetes. These films were used in step 4, where we used a stakeholder co-design approach. This involved a series of structured workshops where the co-design activities were informed by theory and evidence.

On completion of the four-step process, we had developed the DIAMONDS intervention. It is a tailored self-management intervention based on the synthesis of the outputs from the co-design process. The intervention incorporates a digital app, a paper-based workbook and one-to-one coaching designed to meet the needs of people with SMI and co-existing type 2 diabetes.

The intervention development work was underpinned by the MoA theoretical framework, and incorporated systematic reviews, primary qualitative research, expert stakeholder surveys and evidence generated during co-design workshops. The intervention will now be tested for feasibility before undergoing a definitive evaluation in a pragmatic randomised controlled trial.