title: Cost per quality-adjusted life year gained of revision fusion for lumbar pseudoarthrosis: defining the value of surgery.
abstract: METHODS
  Single cohort study of patients undergoing revision fusion for lumbar pseudoarthrosis.
  
  
  OBJECTIVE
  To assess the 2-year comprehensive costs of revision arthrodesis for lumbar pseudoarthrosis at our institution and determine the associated cost per quality-adjusted life year (QALY) gained in this patient population.
  
  
  BACKGROUND
  The proportion of lumbar spine operations involving a fusion procedure has increased over the past 2 decades. Similarly, there has been a corresponding increase in the incidence and prevalence of pseudoarthrosis. However, the cost-effectiveness of revision surgery for pseudoarthrosis-associated back pain has yet to be examined.
  
  
  METHODS
  Forty-seven patients undergoing revision instrumented arthrodesis for pseudoarthrosis-associated back pain were included. Two-year total back-related medical resource utilization, missed work, and health-state values (QALYs, calculated from EuroQuol 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 care-giver work-day losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). The mean total 2-year cost per QALY gained after revision surgery was assessed.
  
  
  RESULTS
  The mean (±SD) duration of time between prior fusion and development of symptomatic pseudoarthrosis was 2.69±3.09 years. None of the patients developed symptomatic pseudoarthrosis after 2 years of revision surgery. A mean cumulative 2-year gain of 0.35 QALYs was reported. The mean (±SD) total 2-year cost of revision fusion was $41,631±$9691 (surgery cost: $23,865±$270; outpatient resource utilization cost: $4885±$2301; indirect cost: $12,879±$8171). Revision instrumented arthrodesis was associated with a mean 2-year cost per QALY gained of $118,945.
  
  
  CONCLUSIONS
  Revision arthrodesis was associated with improved 2-year quality of life in patients with pseudoarthrosis-related back pain. Nevertheless, in our experience revision surgery was shown to be marginally cost-effective at $118,945 per QALY gained.
authors.affiliation: Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN.
authors.forename: Owoicho
authors.initials: O
authors.lastname: Adogwa
authors.forename: Scott L
authors.initials: SL
authors.lastname: Parker
authors.forename: David
authors.initials: D
authors.lastname: Shau
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Mendelhall
authors.forename: Oran
authors.initials: O
authors.lastname: Aaronson
authors.forename: Joseph
authors.initials: J
authors.lastname: Cheng
authors.forename: Clinton J
authors.initials: CJ
authors.lastname: Devin
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: McGirt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001416:Back Pain / Q000209:etiology / Q000601:surgery; D015331:Cohort Studies; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011542:Pseudarthrosis / Q000191:economics / Q000209:etiology / Q000601:surgery*; D019057:Quality-Adjusted Life Years; D012086:Reoperation; D013123:Spinal Fusion / Q000009:adverse effects*; D055815:Young Adult