title: Cost-Utility Analysis of Instrumented Fusion Versus Decompression Alone for Grade I L4-L5 Spondylolisthesis at 1-Year Follow-up: A Pilot Study.
abstract: METHODS
  Retrospective 1-year cost-utility analysis.
  
  
  OBJECTIVE
  To determine the cost-effectiveness of decompression with and without instrumented fusion for patients with grade I degenerative L4-L5 spondylolisthesis at 1-year follow-up.
  
  
  BACKGROUND
  Despite its benefits to health outcomes, lumbar fusion is associated with substantial costs. This study analyzed the cost-effectiveness of instrumented fusion for grade I L4-L5 spondylolisthesis at 1-year follow-up.
  
  
  METHODS
  Four cohorts of 25 patients with grade I L4-L5 degenerative spondylolisthesis were analyzed: cohort 1 (decompression), cohort 2 (decompression with instrumented posterolateral fusion (PLF), cohort 3 (decompression with instrumented posterior lumbar interbody fusion/transforaminal lumbar interbody fusion), and cohort 4 (decompression with instrumented PLF and posterior lumbar interbody fusion/transforaminal lumbar interbody fusion). One-year postoperative health outcomes were assessed based on Visual Analogue Scale, Pain Disability Questionnaire, and EuroQol 5 Dimensions questionnaires. Direct medical costs were estimated using Medicare national payment amounts and indirect costs were based on patient missed work days. Postoperative 1-year cost/utility ratios and incremental cost-effectiveness ratios (ICERs) were calculated. Cost-effectiveness was assessed using a threshold of $100,000/QALY gained.
  
  
  RESULTS
  Compared with preoperative health states, EuroQol 5 Dimensions QALY scores improved for all cohorts (P<0.01). The 1-year cost-utility ratio for cohort 1 was significantly lower ($56,610/QALY gained; P<0.01) than that for cohorts 2 ($116,991/QALY gained), 3 ($109,740/QALY gained), and 4 ($107,546/QALY gained). The 1-year ICERs relative to cohort 1 were: cohort 2 (dominated), cohort 3 ($1,060,549/QALY gained), and cohort 4 ($830,047/QALY gained).
  
  
  CONCLUSIONS
  Decompression without fusion is cost-effective for patients with grade I L4-L5 spondylolisthesis. Decompression with fusion is not cost effective in a 1-year timeframe for these patients based on the threshold. Accordingly, although fusion is beneficial for improving health outcomes in patients with spondylolisthesis, it is not cost-effective when analyzing a 1-year timeframe based on the threshold. The durability of these results must be analyzed with longer term cost-utility analysis studies.
authors.affiliation: *Departments of Orthopaedic and Neurological Surgery, Neurological Institute, Cleveland Clinic Center for Spine Health, Cleveland Clinic†Case Western Reserve University School of Medicine‡Cleveland Clinic Lerner College of Medicine, Cleveland, OH§Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, PA∥Department of Neurological Surgery, Cleveland Clinic, Cleveland, OH.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Alvin
authors.forename: Daniel
authors.initials: D
authors.lastname: Lubelski
authors.forename: Kalil G
authors.initials: KG
authors.lastname: Abdullah
authors.forename: Robert G
authors.initials: RG
authors.lastname: Whitmore
authors.forename: Edward C
authors.initials: EC
authors.lastname: Benzel
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Mroz
mesh_terms: D003362:Cost-Benefit Analysis; D019299:Decompression, Surgical / Q000191:economics*; D003710:Demography; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D019057:Quality-Adjusted Life Years; D013123:Spinal Fusion / Q000191:economics*; D013168:Spondylolisthesis / Q000191:economics* / Q000601:surgery*; D016896:Treatment Outcome