The REDUCE Intervention: The Development of a Person-Centred Cognitive Behavioural Intervention to Improve Ulcer...

Diabetic foot ulcers (DFUs) affect approximately one-quarter of people living with diabetes. They are chronic, recur frequently and are associated with significant psychological distress and behavioural challenges. The REDUCE intervention is a person-centred, cognitive behavioural intervention designed to reduce the risk of DFU recurrence and support ulcer healing. Here, we describe the iterative development and optimisation of REDUCE, from its inception as a group-based intervention to an individually tailored intervention delivered via video call or telephone. We outline key stages of the intervention development, including the integration and modification of a digital maintenance intervention (DMI) designed to support long-term behaviour change and a mixed-methods external pilot trial which informed a full-scale clinical and cost-effectiveness trial.

After initial development, the DMI was the subject of nine 'think-aloud' interviews with patient and public contributors. We conducted an external pilot randomised controlled trial, involving 20 patients with recently healed DFUs randomised in a 2:1 ratio (REDUCE + Usual Care vs. Usual Care only). Data collection included patient-reported outcome measures (baseline and 6 weeks and 3 months post-randomisation) and qualitative interviews with participants and facilitators.

Think-aloud interviews informed key refinements to the DMI to enhance usability and engagement. The pilot trial demonstrated high acceptability of the intervention format and delivery. Patient-reported outcomes suggested positive trends in psychological well-being, footcare behaviours and mood among intervention participants. Qualitative findings highlighted the value of individualised delivery, the importance of facilitator support and varied engagement with the DMI. These insights informed further refinements to REDUCE ahead of a full-scale effectiveness trial.

We provide a comprehensive account of the evolution of the REDUCE intervention and share broader learnings regarding the development of complex behavioural health interventions. The example of REDUCE highlights the value of iterative, multidisciplinary methods and patient involvement in intervention design and offers practical insights for designing digital and remote health interventions.

Patient and public contributors were involved throughout the research described in this manuscript. Key areas of involvement included co-creation of all patient-facing materials, intervention development and informing trial methods.