title: Risk factors for medical complication after lumbar spine surgery: a multivariate analysis of 767 patients.
abstract: METHODS
  Multivariate analysis of prospectively collected registry data.
  
  
  OBJECTIVE
  Using multivariate analysis to determine significant risk factors for medical complication after lumbar spine surgery.
  
  
  BACKGROUND
  Several studies have examined the occurrence of medical complication after spine surgery. However, many of these studies have been done utilizing large national databases. Although these allow for analysis of thousands of patients, potentially influential covariates are not accounted for in these retrospective studies. Furthermore, the accuracy of these retrospective data collection in these databases has been called into question.
  
  
  METHODS
  The Spine End Results Registry (2003–2004) is a collection of prospectively collected data on all patients who underwent spine surgery at our two institutions. Extensive demographic and medical information were prospectively recorded as described previously by Mirza et al. Complications were defined in detail a priori and were prospectively recorded for at least 2 years after surgery. We analyzed risk factors for medical complication after lumbar spine surgery using univariate and multivariate analysis.
  
  
  RESULTS
  We analyzed data from 767 patients who met out inclusion criteria. The cumulative incidences of complication after lumbar spine surgery per organ system are as follows: cardiac, 13%; pulmonary, 7%; gastrointestinal, 6.7%; neurological, 8.2%; hematological, 17.5%; and urologic complications, 10.3%. The occurrence of cardiac or respiratory complication after lumbar spine surgery was significantly associated with death within 2 years (relative risk: 6.09 and 10.9, respectively). Several significant risk factors were identified for organ-specific complications. Among these, surgical invasiveness appeared to be the largest risk factor for cardiac, pulmonary, neurological, and hematological complications.
  
  
  CONCLUSIONS
  Risk factors identified in this study can be beneficial to clinicians and patients alike when considering surgical treatment of the lumbar spine. Future analyses and models that predict the occurrence of medical complication after lumbar spine surgery may be of further benefit for surgical decision making.
authors: Department of Orthopedics and Sports Medicine, University of Washington, Seattle, WA, USA. mjl3000@uw.edu
authors: Michael J
authors: MJ
authors: Lee
authors: Jacques
authors: J
authors: Hacquebord
authors: Anuj
authors: A
authors: Varshney
authors: Amy M
authors: AM
authors: Cizik
authors: Richard J
authors: RJ
authors: Bransford
authors: Carlo
authors: C
authors: Bellabarba
authors: Mark A
authors: MA
authors: Konodi
authors: Jens
authors: J
authors: Chapman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D019637:Orthopedic Procedures / Q000009:adverse effects*; D018579:Patient Selection; D011183:Postoperative Complications / Q000209:etiology*; D011446:Prospective Studies; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014861:Washington; D055815:Young Adult