Cost-effectiveness of surgical treatment of adult spinal deformity: comparison of posterior-only versus anteroposterior approach

BACKGROUND CONTEXT: Considerable debate exists regarding the optimal surgical approach for adult spinal deformity (ASD). It remains unclear which approach, posterior-only or combined anterior-posterior (AP), is more cost-effective. Our goal is to determine the 2-year cost per quality-adjusted life year (QALY) for each approach. PURPOSE: To compare the 2-year cost-effectiveness of surgical treatment for ASD between the posterior-only approach and combined AP approach. STUDY DESIGN: Retrospective economic analysis of a prospective, multicenter database PATIENT SAMPLE: From a prospective, multicenter surgical database of ASD, patients undergoing five or more level fusions through a posterior-only or AP approach were identified and compared. METHODS: QALYs gained were determined using baseline, 1-year, and 2-year postoperative Short Form 6D. Cost was calculated from actual, direct hospital costs including any subsequent readmission or revision. Cost-effectiveness was determined using cost/QALY gained. RESULTS: The AP approach showed significantly higher index cost than the posterior-only approach ($84,329 vs. $64,281). This margin decreased at 2-year follow-up with total costs of $89,824 and $73,904, respectively. QALYs gained at 2 years were similar with 0.21 and 0.17 in the posterior-only and the AP approaches, respectively. The cost/QALY at 2 years after surgery was significantly higher in the AP approach ($525,080) than in the posterior-only approach ($351,086). CONCLUSIONS: We assessed 2-year cost-effectiveness for the surgical treatment through posterior-only and AP approaches. The posterior-only approach is less expensive both for the index surgery and at 2-year follow-up. The QALY gained at 2-years was similar between the two approaches. Thus, posterior-only approach was more cost-effective than the AP approach under our study parameters. However, both approaches were not cost-effective at 2-year follow-up. (C) 2020 Elsevier Inc. All rights reserved.