Cost-effectiveness of endovascular versus open surgery for chronic limb-threatening ischemia.

Background: Revascularization for Chronic Limb-Threatening Ischemia (CLTI) may be performed with an endovascular (Endo) or open surgical (Bypass) approach. Objective: To evaluate the cost-effectiveness of Endo versus Bypass surgery for CLTI using data from the Best Endovascular versus Best Surgical Therapy for Patients with CLTI (BEST-CLI) trial. Methods: We developed an individual-level continuous time Markov model that included health states representing the occurrence of adjudicated clinical events from BEST-CLI. Rates of clinical outcomes and health utilities were derived directly from trial data. Costs came from Medicare insurance claims data and physician fee schedule. We calculated the incremental cost per life years gained, incremental quality-adjusted life years (QALYs) gained, incremental net monetary benefit (INMB) and cost per major events of amputation, revascularization, and myocardial infarction (MI) or stroke avoided over a 5- and 10-year time horizon. Sensitivity analyses were performed using a Monte Carlo simulation. Results: In base case analyses conducted over a 5-year time horizon, the mean per person direct medical costs were $227,341 (95% Credible Interval [CrI]: $173,075, $291,443) for Bypass and $243,614 (95% CrI: $190,112, $305,605) for Endo. The mean survival per person was 3.91 years (95% CrI: 3.78, 4.03) for Bypass and 3.88 years (95% CrI: 3.68, 4.06) for Endo. This resulted in Endo being dominated by Bypass surgery with respect to costs per life year gained. The mean QALYs per person were 2.48 (95% CrI: 1.11, 3.49) for Bypass and 2.54 (95% CrI: 1.39, 3.40) for Endo, resulting in an incremental costs per QALY gained of $263,973/QALY and an INMB of -$10,109 (95% CrI: -$168,908, $157,433) at a $100,000/QALY willingness-to-pay threshold for Endo vs. Bypass. The results over 10 years were consistent with those of the 5-year follow-up. In the Monte Carlo simulation, there was only a 55% chance that Bypass was more cost-effective than Endo. Conclusion: In the base case analysis, Bypass was the preferred strategy with respect to survival and QALYs, at conventional willingness to pay thresholds. There was substantial uncertainty around these estimates in probabilistic sensitivity analysis, justifying future research to identify subgroups for whom each of these approaches may definitively be cost-effective.