title: Cost per quality-adjusted life year gained of laminectomy and extension of instrumented fusion for adjacent-segment disease: defining the value of surgical intervention.
abstract: OBJECTIVE
  Over the past decade, there has been a dramatic increase in the number of spinal fusions performed in the US and a corresponding increase in the incidence of adjacent-segment disease (ASD). Surgical management of symptomatic ASD consists of decompression of neural elements and extension of fusion. It has been shown to have favorable long-term outcomes, but the cost-effectiveness remains unclear. In this study, the authors set out to assess the cost-effectiveness of revision surgery in the treatment of ASD over a 2-year period.
  
  
  METHODS
  Fifty patients undergoing neural decompression and extension of fusion construct for ASD-associated back and leg pain were included in the study. Two-year total back-related medical resource utilization, missed work, and health state values (quality-adjusted life years [QALYs], calculated from the EQ-5D with US valuation) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost), and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Mean total 2-year cost per QALY gained after revision surgery was assessed.
  
  
  RESULTS
  The mean (± SD) interval between prior fusion and revision surgery for ASD was 3.07 ± 2.02 years. A mean cumulative 2-year gain of 0.76 QALYs was observed after revision surgery. The mean total 2-year cost of extension of fusion constructs was $47,846 ± $32,712 (surgery cost: $24,063 ± $300; outpatient resource utilization cost: $4175 ± $3368; indirect cost: $19,607 ± $32,187). Revision decompression and extension of fusion was associated with a mean 2-year cost per QALY gained of $62,955.
  
  
  CONCLUSIONS
  In the authors' practice, revision decompression and extension of fusion provided a significant gain in health state utility for patients with symptomatic ASD, with a 2-year cost per QALY gained of $62,995. When indicated, revision surgery for ASD is a valuable treatment option for patients experiencing back and leg pain secondary to ASD. The findings provide a value measure of surgery that can be compared with future cost-per-QALY-gained studies of medical management or alternative surgical approaches.
authors: Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
authors: Owoicho
authors: O
authors: Adogwa
authors: Scott L
authors: SL
authors: Parker
authors: David N
authors: DN
authors: Shau
authors: Stephen K
authors: SK
authors: Mendenhall
authors: Clinton J
authors: CJ
authors: Devin
authors: Joseph S
authors: JS
authors: Cheng
authors: Matthew J
authors: MJ
authors: McGirt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001416:Back Pain / Q000191:economics / Q000453:epidemiology / Q000601:surgery; D003362:Cost-Benefit Analysis; D019299:Decompression, Surgical / Q000191:economics / Q000706:statistics & numerical data; D055111:Failed Back Surgery Syndrome / Q000191:economics / Q000453:epidemiology / Q000601:surgery; D005260:Female; D006296:Health Services / Q000191:economics / Q000706:statistics & numerical data; D006304:Health Status; D006801:Humans; D015994:Incidence; D007796:Laminectomy / Q000191:economics* / Q000706:statistics & numerical data; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019057:Quality-Adjusted Life Years; D012086:Reoperation / Q000191:economics / Q000706:statistics & numerical data; D013122:Spinal Diseases / Q000191:economics / Q000453:epidemiology / Q000601:surgery; D013123:Spinal Fusion / Q000191:economics* / Q000706:statistics & numerical data; D055815:Young Adult