Abstract
INTRODUCTION: The objective of this study was to assess the cost-effectiveness of the d-Nav Insulin Guidance Service (Hygieia Inc.), a system designed to improve glycemic control via the use of insulin titration, in people with diabetes at risk of developing neuropathic foot ulcers. METHODS: A Markov model containing four health states (no ulcer, uninfected ulcer, infected ulcer, and amputation) was developed to compare d-Nav with current National Health Service standard care. Patient movement between the health states was governed by event rates taken from the wider literature. Both the healing rate for uninfected ulcers and the rate of recurrence for uninfected ulcers were directly influenced by the patient's glycated hemoglobin (HbA1c). Separate mean HbA1c values were assigned to treatment and control patients and taken from a single-arm study that examined the effect of d-Nav on the outcomes of 122 patients, with HbA1c for control patients based on values recorded in the 12-month period prior to the study and HbA1c for d-Nav based on values recorded during the trial. Weekly cycles were applied, and patient resource use and quality-adjusted life years (QALYs) were estimated over a 3-year time horizon. Univariate sensitivity analysis was undertaken. RESULTS: In the base case, d-Nav was cost-saving and produced more QALYs than standard care, with a total net monetary benefit value of £1459 per patient. Univariate analysis indicated that the model results are relatively robust to variations in underlying parameters, with patient HbA1c having the most significant impact on outcomes. CONCLUSION: Interventions that aim to improve glycemic control, such as d-Nav, appear to be a cost-effective use of healthcare resources when targeted at those with poor glycemic control at high risk of developing foot ulcers. FUNDING: Hygieia Inc.