Improving self and clinical management of comorbid diabetes during cancer treatments: a qualitative interview study with patients and clinicians to identify theory-based intervention targets, strategies and implementation options

Background Many people living with diabetes will also develop cancer in their lifetime.

The research evidence and our clinical and PPI consultations indicate that patients and health care professionals (HCPs) struggle to manage diabetes during anti-cancer therapies, and that cancer patients with pre-existing diabetes have poorer morbidity and mortality outcomes.

No research has developed interventions specifically aimed at addressing the challenges to effective self or clinical management of diabetes during cancer treatments. Our proposed research aims to begin addressing this gap.

Improved diabetes management has potential to reduce the risk of adverse events and complications like infections, and thus treatment dose reduction or stoppage, and ultimately to positively impact cancer outcomes and survival.

Effective management of diabetes during periods of cancer treatment will also mitigate risk of diabetic complications (e.g. retinopathy) during cancer survivorship.

Improved morbidity outcomes would reduce the cost of health care and medicines for this sizeable and growing comorbid patient group.

Aims To explore patients and HCPs perceived challenges and enablers to, and suggestions for ways to support, effective self and clinical management of comorbid diabetes during cancer treatments To identify potential strategies to promote effective self and clinical management of comorbid diabetes during cancer treatments Methods We will interview n=30-40 patients with pre-existing diabetes (type-1 or type-2) who also have a diagnosis of breast, prostate or colorectal cancer, and are receiving anti-cancer treatment currently or within the last 2-years.

We will also interview n=25-30 HCPs with experience of caring for this patient group (e.g. oncologists, diabetologists, radiographers, specialist-nurses, dieticians, GPs, practice-nurses). Patients and HCPs will participate in one individual face-to-face in-depth qualitative semi-structured interview.

Open-ended interview topic guides will be informed by the Theoretical-Domains/Mechanisms-of-Action framework, which will be used to guide data collection and analysis in conjunction with related behavioural intervention-development resources such as the Behaviour-Change-Wheel (BCW) and Theory-and-Techniques-Tool.

We will use the Framework method to analyse the interviews, which allows themes and codes to be both pre-selected and generated inductively.

A PPI-panel will collaborate, advise and feedback on all stages of the research including design of the interview guides, data analysis and interpretation, and co-producing dissemination outputs.

Outputs, dissemination and anticipated impact We will identify: (1) perceived challenges and enablers to effective self and clinical management of diabetes during cancer treatments (i.e. intervention targets); (2) pertinent intervention Behaviour-Change-Techniques (BCTs) best-suited to addressing these targets; and (3) implementation options, in terms of relevant policy levers (from BCW), and relevant possible modes, through which the different identified BCTs could be delivered.

These knowledge outputs will be disseminated via: (1) lay summaries; (2) presentations at patient & public, clinical, and academic meetings/events/conferences; and (3) publications in practitioner magazines and peer-reviewed journals.

Routes to impact include: (1) feedback to the recruiting NHS-Trusts and GP-surgeries of learning that could lead to local improvements to care for this comorbid patient group; (2) collaboration with Diabetes-UK and Macmillan-Cancer-Support to enhance their clinical and patient information-resources; and (3) next-step research to develop and evaluate the intervention strategies identified in this study.