Tibial nerve decompression for the prevention of the diabetic foot: a cost–utility analysis using Markov model simulations

OBJECTIVE: To determine whether tibial neurolysis performed as a surgical intervention for patients with diabetic neuropathy and superimposed tibial nerve compression in the prevention of the diabetic foot is cost-effective when compared with the current prevention programme. DESIGN: A baseline analysis was built on a 5-year model to determine the cumulative incidence of foot ulcers and amputations with each strategy. Subsequently, a cost-effectiveness analysis and cohort-level Markov simulations were conducted with a model composed of 20 6-month cycles. A sensitivity analysis was also performed. SETTING: A Markov model was used to simulate the effects of standard prevention compared with tibial neurolysis on the long-term costs associated with foot ulcers and amputations. This model included eight health states. PARTICIPANTS: Each cohort includes simulated patients with diabetic neuropathy at different levels of risk of developing foot ulcers and amputations. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the long-term trends concerning the development of ulcers and amputations with each strategy. The secondary outcome measures were quality adjusted life years (QALYs), incremental cost-effectiveness and net monetary benefits of the optimal strategy. RESULTS: When compared with standard prevention, for a patient population of 10 000, surgery prevented a simulated total of 1447 ulcers and 409 amputations over a period of 5 years. In a subsequent analysis that consisted of 20 6-month cycles (10 years), the incremental cost of tibial neurolysis compared with current prevention was $12 772.28; the incremental effectiveness was 0.41 QALYs and the incremental cost-effectiveness ratio was $31 330.78. Survival was 73% for those receiving medical prevention compared with 95% for those undergoing surgery. CONCLUSION: These results suggest that among patients with diabetic neuropathy and superimposed nerve compression, surgery is more effective at preventing serious comorbidities and is associated with a higher survival over time. It also generated greater long-term economic benefits.