title: Early predictors of lumbar spine surgery after occupational back injury: results from a prospective study of workers in Washington State.
abstract: METHODS
  Prospective population-based cohort study.
  
  
  OBJECTIVE
  To identify early predictors of lumbar spine surgery within 3 years after occupational back injury.
  
  
  BACKGROUND
  Back injuries are the most prevalent occupational injury in the United States. Few prospective studies have examined early predictors of spine surgery after work-related back injury.
  
  
  METHODS
  Using Disability Risk Identification Study Cohort (D-RISC) data, we examined the early predictors of lumbar spine surgery within 3 years among Washington State workers, with new workers compensation temporary total disability claims for back injuries. Baseline measures included worker-reported measures obtained approximately 3 weeks after claim submission. We used medical bill data to determine whether participants underwent surgery, covered by the claim, within 3 years. Baseline predictors (P < 0.10) of surgery in bivariate analyses were included in a multivariate logistic regression model predicting lumbar spine surgery. The area under the receiver operating characteristic curve of the model was used to determine the model's ability to identify correctly workers who underwent surgery.
  
  
  RESULTS
  In the D-RISC sample of 1885 workers, 174 (9.2%) had a lumbar spine surgery within 3 years. Baseline variables associated with surgery (P < 0.05) in the multivariate model included higher Roland-Morris Disability Questionnaire scores, greater injury severity, and surgeon as first provider seen for the injury. Reduced odds of surgery were observed for those younger than 35 years, females, Hispanics, and those whose first provider was a chiropractor. Approximately 42.7% of workers who first saw a surgeon had surgery, in contrast to only 1.5% of those who saw a chiropractor. The area under the receiver operating characteristic curve of the multivariate model was 0.93 (95% confidence interval, 0.92-0.95), indicating excellent ability to discriminate between workers who would versus would not have surgery.
  
  
  CONCLUSIONS
  Baseline variables in multiple domains predicted lumbar spine surgery. There was a very strong association between surgery and first provider seen for the injury even after adjustment for other important variables.
authors.affiliation: Department of Orthopaedics, Geisel School of Medicine at Dartmouth College, Lebanon, NH 03756, USA. Benjamin.J.Keeney@Dartmouth.edu
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Keeney
authors.forename: Deborah
authors.initials: D
authors.lastname: Fulton-Kehoe
authors.forename: Judith A
authors.initials: JA
authors.lastname: Turner
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Wickizer
authors.forename: Kwun Chuen Gary
authors.initials: KC
authors.lastname: Chan
authors.forename: Gary M
authors.initials: GM
authors.lastname: Franklin
mesh_terms: D000328:Adult; D019567:Back Injuries / Q000150:complications / Q000601:surgery*; D001416:Back Pain / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D004185:Disability Evaluation; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D016015:Logistic Models; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D060051:Occupational Injuries / Q000150:complications / Q000601:surgery*; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D011795:Surveys and Questionnaires; D013997:Time Factors; D014861:Washington; D014942:Workers' Compensation / Q000706:statistics & numerical data