How the study works

This study has six work streams:

1. To identify factors that promote or inhibit self-management behaviours in people with severe mental illness and co-existing long-term conditions, through a literature review and interviews with patients, carers and healthcare staff
2. To design self-management interventions for diabetes and for chronic lung disease that address these factors, through selecting appropriate intervention targets and behaviour change techniques, and using co-design and iterative experimental testing methods (to improve acceptability, feasibility and potential effectiveness)
3. To refine and optimise the design of the diabetes self-management intervention; and optimise trial design through a feasibility trial
4. To determine clinical and cost-effectiveness of the diabetes self-management intervention through a randomised controlled trial, with internal pilot
5. To estimate longer-term cost-effectiveness by developing an economic model to predict health outcomes and costs for people with severe mental illness and diabetes
6. To develop a framework for adapting self-management interventions for other long-term conditions in severe mental illness, through expert workshops and synthesis of learning from across the programme

The DIAMONDS programme is supported by a wider programme of work on mental and physical multimorbidity, and draws on expertise from the Patient and Public Involvment Panel, DIAMONDS VOICE, the University of York, the University of Leeds, the University of Southampton, and Bradford District Care NHS Foundation Trust.

The study has a multi-disciplinary project team with representation from health economics, endocrinology, epidemiology, DIAMONDS VOICE, psychiatry, research methodology, health policy, general practice and statistics.  In addition the study has an independent Study Steering Group that supervises the study team on behalf of the funder (National Institute for Health Research) and the sponsoring institution, the University of York.

Workstream one involves a literature review and an interview study (called DIAMONDS Quest).  Three groups of people are being interviewed for DIAMONDS Quest: 32-42 people with severe mental illness and diabetes, 15-20 relatives or friends who provide support, and 15-20 healthcare staff who provide or commission services for this population.

Several NHS Mental Health Trusts and GP practices are collaborating in the study by identifying suitable people to be interviewed.

The findings from workstream one will be used to develop a diabetes self-management intervention for people with severe mental illness and type 2 diabetes.  The effectiveness and cost-effectiveness of this intervention will then be explored.  Following this we will explore the generalisability of our approach to other long-term conditions in people with severe mental illness, through design of a self-management intervention for another patient group, chronic obstructive pulmonary disease (COPD), and development of a framework to adapt the intervention for other long-term conditions.

If the diabetes self-management programme is shown to be worthwhile, we will develop a detailed plan for its implementation and uptake in the NHS. We will disseminate our findings to all those who are going to be involved in commissioning or using the programme, working closely with a wide range of stakeholders.  This research will have the potential to improve self-management and outcomes for people with severe mental illness and diabetes, and for those living with other comorbid long-term conditions, helping to reduce health care costs and health inequalities.