title: Patient comorbidities and complications after spinal surgery: a societal-based cost analysis.
abstract: METHODS
  Prospective observational study.
  
  
  OBJECTIVE
  To determine how patient comorbidities and perioperative complications after spinal surgery affect the health care costs to society.
  
  
  BACKGROUND
  Despite efforts to reduce adverse events related to spinal surgery, complications are common and significantly increased by patient comorbidities.
  
  
  METHODS
  Patients who underwent spinal surgery at a tertiary academic center during a 6-month period (May 2008 to December 2008) were prospectively followed. All demographic data, comorbidities, procedural information, and complications to 30-day follow-up were recorded. Diagnosis-Related Group codes and Current Procedural Terminology codes were captured for each patient. Direct costs were estimated from a societal perspective, using 2008 Medicare rates of reimbursement. A multivariable analysis was performed to assess the impact of specific patient comorbidities and complications on total health care costs.
  
  
  RESULTS
  A total of 226 cases were analyzed. The mean cost of care for cases with complications was greater than that for cases without complications ($13,518.35 [95% confidence interval (CI), $9378.80-$17,657.90]; P < 0.0001). These results were consistent across degenerative, traumatic, and tumor/infection preoperative diagnoses. Cases with major complications were more costly than those with minor complications ($13,714.88 [CI, $6353.02-$21,076.74]; P = 0.0001). Systemic malignancy and preoperative neurological comorbidity were each associated with an increase in the cost of care ($7919 [CI, $2073-$15,225]; P = 0.006] and $5508 [CI, $814-$11,198; P = 0.02]), respectively, when compared with a baseline cost of care derived from all cases in the database. The cost of care was increased by pulmonary complications ($7233 [CI, $3982.53-$11,152.88]; P < 0.0001), instrumentation malposition ($6968 [CI, $1705.90-$14,277.16]; P = 0.0062), new neurological deficit ($4537 [CI, $863.95-$9274.30]; P = 0.013), and by wound infection ($4067 [CI, $1682.79-$6872.39]; P = 0.0004), after adjustment for covariates.
  
  
  CONCLUSIONS
  Both minor and major complications were found to increase the cost of care in a prospective assessment of spine surgery complications. Specific patient comorbidities and perioperative complications are associated with significant increases in the total cost of care to society.
authors: Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors: Robert G
authors: RG
authors: Whitmore
authors: James
authors: J
authors: Stephen
authors: Sherman C
authors: SC
authors: Stein
authors: Peter G
authors: PG
authors: Campbell
authors: Sanjay
authors: S
authors: Yadla
authors: James S
authors: JS
authors: Harrop
authors: Ashwini D
authors: AD
authors: Sharan
authors: Mitchell G
authors: MG
authors: Maltenfort
authors: John K
authors: JK
authors: Ratliff
mesh_terms: D000328:Adult; D000368:Aged; D015897:Comorbidity; D003365:Costs and Cost Analysis; D003953:Diagnosis-Related Groups / Q000191:economics; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs; D006801:Humans; D006949:Hyperlipidemias / Q000191:economics*; D006973:Hypertension / Q000191:economics*; D007349:Insurance, Health, Reimbursement / Q000191:economics; D008171:Lung Diseases / Q000191:economics*; D008297:Male; D006278:Medicare / Q000191:economics; D008875:Middle Aged; D015999:Multivariate Analysis; D009985:Orthopedics; D011183:Postoperative Complications / Q000191:economics*; D011446:Prospective Studies; D012189:Retrospective Studies; D013131:Spine / Q000601:surgery*; D014481:United States