title: Factors influencing 2-year health care costs in patients undergoing revision lumbar fusion procedures.
abstract: OBJECTIVE
  Revision lumbar fusion procedures are technically challenging and can be associated with tremendous health care resource utilization and cost. There is a paucity of data regarding specific factors that significantly contribute to increased cost of care. In light of this, the authors set out to identify independent risk factors predictive of increasing 2-year direct health care costs after revision lumbar fusion.
  
  
  METHODS
  One hundred fifty patients undergoing revision instrument-assisted fusion for adjacent-segment disease (50 cases), pseudarthrosis (47 cases), or same-level stenosis (53 cases) were included in this study. Patient demographics, comorbidities, preoperative health states as assessed by patient-reported outcome questionnaires and perioperative complications were collected and analyzed. Two-year back-related medical resource utilization and direct health care costs were assessed. The independent association of all variables to increasing cost was assessed using multivariate linear regression analysis.
  
  
  RESULTS
  There was a wide range ($24,935-$63,769) in overall 2-year direct costs for patients undergoing revision lumbar fusion (mean $32,915 ± $8344 [± SD]). Preoperative variables independently associated with 2-year direct health care costs included diagnosis of congestive heart failure, more severe leg pain (visual analog scale), greater back-related disability (Oswestry Disability Index), and worse mental health (12-Item Short Form Health Survey Mental Component Summary score). There was a 1.1- to 1.2-fold increase in cost for patients in the greatest quartiles compared with those in the lowest quartiles for these variables. Surgical site infection, return to the operating room, and spine-related hospital readmission during the 90-day global health period were postoperative variables independently associated with 2-year cost. Patients in the greatest versus lowest quartiles had a 1.7- to 1.9-fold increase in cost for these variables.
  
  
  CONCLUSIONS
  Revision lumbar fusion can be associated with considerable 2-year health care costs. These costs can also vary widely among patients, as evidenced by the 2.6-fold overall cost range in this series. Although comorbidities and preoperative severity of disease states contribute to cost of care, the primary drivers of increased cost include perioperative complications such as surgical site infection, return to the operating room, and readmission during the global health period. Measures focused on health service improvement will be most successful in reducing the cost of care for patients undergoing revision lumbar fusion.
authors.affiliation: Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN 37232-8618, USA. scott.parker@vanderbilt.edu
authors.forename: Scott L
authors.initials: SL
authors.lastname: Parker
authors.forename: David N
authors.initials: DN
authors.lastname: Shau
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Mendenhall
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: McGirt
mesh_terms: D000368:Aged; D003365:Costs and Cost Analysis; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006295:Health Resources / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000191:economics; D011183:Postoperative Complications / Q000191:economics* / Q000601:surgery; D011542:Pseudarthrosis / Q000191:economics / Q000601:surgery; D019057:Quality-Adjusted Life Years; D012086:Reoperation / Q000191:economics; D013123:Spinal Fusion / Q000191:economics*; D013130:Spinal Stenosis / Q000191:economics / Q000601:surgery; D013714:Tennessee; D016896:Treatment Outcome