title: Cost-Effectiveness of Lumbar Spondylolisthesis Surgery at 2-Year Follow-up.
abstract: The purpose of this study was to determine the cost/quality-adjusted life-year (QALY) of the operative treatment of lumbar spondylolisthesis and identify factors associated with cost-effectiveness at 2 years.
  
  
  
  We evaluated patients who underwent surgery for spondylolisthesis. The QALY was determined from the EQ5D. Outcomes were also assessed using the Oswestry Disability Index (ODI). Surgical, neuromonitoring, and anesthesia Current Procedural Terminology (CPT) codes as well as hospital Diagnosis-Related Group codes were used to determine the Medicare direct care costs of surgery. Indirect costs were modeled based on existing literature. A discounting rate of 3% was applied. Analysis was performed to determine which factors were associated with a cost/QALY less than $100,000.
  
  
  
  There were 44 patients who underwent surgery for either degenerative (30) or isthmic spondylolisthesis (14). There were 27 women and 17 men, with an average age at surgery of 59.7 years (standard deviation [SD] = 14.69) and an average follow-up of 2 years (SD = 0.82). The average postoperative improvement in ODI was 24.77 (SD = 23.9), and change in QALY was 0.43 (SD = 0.30). The average cost/QALY at 2 years for direct care costs was $89,065. The average cost/QALY at 2 years for direct plus indirect costs was $112,588. Higher preoperative leg pain and greater leg pain change was associated with a cost/QALY <$100,000 (p < .005, p < .028). The cost-effective group had a higher proportion of patients with disease extent of two or more levels (p = .021). When comparing surgical techniques of anterior-posterior and posterior only, there was no difference in cost-effectiveness.
  
  
  
  Spondylolisthesis surgery is cost-effective at 2 years, with a QALY change of 0.43 and a direct cost/QALY of $89,065. Higher preoperative leg pain and larger extent of disease was associated with cost-effectiveness.
  
  
  
  IV.
authors.affiliation: Columbia University Medical Center, 630 West 168th St, New York, NY 10032, USA. Electronic address: cdr2112@columbia.edu.
authors.forename: Charla R
authors.initials: CR
authors.lastname: Fischer
authors.affiliation: Columbia University Medical Center, 630 West 168th St, New York, NY 10032, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Cassilly
authors.affiliation: Columbia University Medical Center, 630 West 168th St, New York, NY 10032, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Dyrszka
authors.affiliation: NYU Hospital for Joint Diseases, 333 E 38th St, New York, NY 10016, USA.
authors.forename: Yuriy
authors.initials: Y
authors.lastname: Trimba
authors.affiliation: NYU Hospital for Joint Diseases, 333 E 38th St, New York, NY 10016, USA; Oregon Health and Sciences University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Austin
authors.initials: A
authors.lastname: Peters
authors.affiliation: NYU Hospital for Joint Diseases, 333 E 38th St, New York, NY 10016, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Goldstein
authors.affiliation: NYU Hospital for Joint Diseases, 333 E 38th St, New York, NY 10016, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Spivak
authors.affiliation: NYU Hospital for Joint Diseases, 333 E 38th St, New York, NY 10016, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Bendo
mesh_terms: D000328:Adult; D000368:Aged; D003362:Cost-Benefit Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D013123:Spinal Fusion / Q000191:economics*; D013168:Spondylolisthesis / Q000601:surgery*; D014481:United States
keywords: Cost-effectiveness; Cost/QALY; Spinal fusion; Spondylolisthesis