Cost-Effectiveness of Anterior and Posterior Surgical Approaches for Cervical Spondylotic Myelopathy: An Economic Evaluation of a Randomized Clinical Trial

BACKGROUND AND OBJECTIVES: Surgery for cervical spondylotic myelopathy improves quality of life but remains expensive. We conducted a cost-effectiveness analysis of patients treated with anterior cervical diskectomy/fusion (ACDF), posterior cervical decompression/fusion (PCDF), and laminoplasty (LP) in the Cervical Spondylotic Myelopathy Surgical (CSM-S) Trial, a randomized trial comparing surgical approaches for cervical spondylotic myelopathy. METHODS: In the trial, patients were randomized (2:3) to anterior (ACDF) or posterior surgery (LP or PCDF, at surgeon's discretion). A cost-effectiveness analysis was performed from a societal perspective with a 1-year time horizon, including only US patients as-treated. Cumulative costs were estimated using patient data on utilization and lost productivity using a human capital approach. Direct costs were calculated using 2022 Medicare rates for professional fees and cost-to-charge ratios for hospital services. Quality-adjusted life-years (QALYs) were calculated from patient responses to the EuroQol-5-Dimensions instrument at baseline and 3, 6, and 12 months postoperatively. Incremental cost-effectiveness ratio analysis was performed with bootstrapping to address uncertainty. RESULTS: Of 163 total patients enrolled in the CSM-S Trial, 153 from the United States (mean age, 62 years; 80 (52%) female) were included as-treated (ACDF = 61, PCDF = 64, LP = 28) in a cost-effectiveness analysis. Economic data were not available for 9 patients. The remaining 144 patients treated (ACDF = 55, PCDF = 61, LP = 28) had cost data through a 1-year follow-up. Mean hospitalization costs were higher after PCDF than ACDF and LP ($33 410 vs $26 468 vs $25 550; P < .001). Mean total costs were higher after PCDF than ACDF and LP ($62 383 vs $53 074 vs $47 426; P = .017). LP yielded greater QALY gains than ACDF (0.792 vs 0.732; P = .08) and PCDF (0.792 vs 0.698; P = .01). At a willingness-to-pay threshold of $150 000/QALY-gained, the probability that LP was cost-effective compared with PCDF was 99.7% and the probability compared with ACDF was 96%. CONCLUSION: In the CSM-S Trial, LP yielded greater 1-year quality-of-life improvements at lower costs than PCDF and ACDF.