Title: An evidence-based evaluation of the clinical and cost effectiveness of foot ulcer risk assessment and structured care interventions for people with diabetes.
Funder: Chief Scientist Office, Scotland

Abstract: Diabetes-related foot ulcers give rise to considerable morbidity and generate a high monetary cost for health and social care services. They are known to precede 80% of diabetes-related lower extremity amputations (LEAs). The recommendations from diabetes clinical guidelines are mostly based on consensus rather than data-driven and they omit important studies which contain evidence of effects which could improve patient outcomes. Our research objectives are to produce an evidence clinical pathway by; I. Extending (developing ) our existing prognostic model into a CPR and externally validating it II. Conducting a survival analysis of the time to ulceration to inform the economic model III. Performing an overview of systematic reviews to identify the effects and costs for available interventions (simple interventions such as pressure relieving insoles and complex interventions such as specialist foot care teams): Then; IV. Combining the evidence from i, ii and iii in a cost effectiveness decision model framework and analysing alternative clinical and cost effective regimens at different monitoring frequencies V. Conducting a value of information analysis. Our team has the use of an individual Patient Data (IPD) dataset collected from patients with diabetes from studies conducted worldwide (acronym PODUS). We developed and validated a predictive model involving only 3 predictor variables; insensitivity to a 10-g monofilament; absent pedal pulses; and a history of ulceration or LEA. These are all easy and cheap to obtain and therefore likely to be used in clinical practice. However the results are expressed as summary odds ratios which do not readily allow clinicians to assess risk. We propose to develop a clinical prediction rule by producing a simple scoring system for use in clinical practice. Another problem with the risk assessment for foot disease in diabetes is the frequency that people with diabetes should be assessed. Monitoring intervals will be calculated by our team using the PODUS dataset and in consultation with clinical colleagues. If data over and above the PODUS data are required we can collect follow-up data from patients who consented to their medical and foot health records being monitored. We will also perform an overview of evidence from systematic reviews of interventions (simple and complex) which may prevent the development of foot ulcers. We will then construct a decision analytic economic model incorporating the evidence based clinical pathway and conduct cost effectiveness analyses comparing it with current practice. The economic model will include the expected costs, effects and cost-effectiveness of the evidence based pathway and those recommended in UK Clinical diabetes guidelines from the perspective of the NHS. Finally, our economic model will include a Bayesian Value of Information Analysis (VOI). This type of analysis determines the value to society of the collection of further information concerning the costs, effectiveness and cost-effectiveness of the CPR and structured care for people with diabetes.

Lay abstract: People with diabetes sometimes have problems with their feet which become serious and this makes getting around harder and life less enjoyable. It might be possible to avoid foot problems by having regular foot checks by doctors, podiatrists or nurses but at the moment it is not clear how useful this is or often it needs to be done. People who learn they might go on to have foot problems expect to be given treatment to stop the problem happening in the first place. But unfortunately the best way to avoid foot problems is not known and more research is needed. But before a large, expensive study called a clinical trial can be done there is a need to study the different ways people with diabetes can have foot care from the NHS. We have begun to research this area and have found 3 simple things will identify people who are likely to develop a foot ulcer. We now plan to build on this work by making our research results easier for doctors and nurses and podiatrists to use. Then we will look at published articles to see whether certain treatments or care plans stop foot problems from developing and which treatments are of most value to patients and the NHS. Finally we want to know if any more research, particularly a large clinical trial would be good value for money. We want to know; 1. How often should people with diabetes have their feet examined by NHS staff? 2. What are the best things for patients and NHS staff to do to stop foot problems from happening? 3. Is a large clinical trial likely to produce information that is good value for money? Our research will culminate in recommendations for clinical practice and future research.

Research activity codes: 4.2 EVALUATION OF MARKERS AND TECHNOLOGIES
Health categories: METABOLIC AND ENDOCRINE;SKIN