title: Prognostic factors associated with minimal improvement following acute whiplash-associated disorders.
abstract: METHODS
  Retrospective clinical cohort study.
  
  
  OBJECTIVE
  To identify the prognostic factors associated with a poor response to treatment in the early stages of a whiplash-associated disorder (WAD).
  
  
  BACKGROUND
  Several demographic and clinical factors related to recovery following acute WADs have been identified. However, few longitudinal studies have investigated a multivariable model of recovery that includes socio-demographic, treatment, clinical, and nonclinical factors.
  
  
  METHODS
  A study cohort of 2,185 patients with acute or subacute WADs presenting to 48 rehabilitation clinics in 6 Canadian provinces were investigated for factors associated with failure to demonstrate a minimally important clinical change (10%) in the Canadian Back Institute Questionnaire (CBIQ) score between the initial and discharge rehabilitation visits.
  
  
  RESULTS
  Multivariable analysis revealed eight prognostic factors associated with a negative outcome: 1) older age, 2) female gender, 3) increasing lag time between injury date and presentation for treatment, 4) initial pain location, 5) province of injury, 6) higher initial pain intensity, 7) lawyer involvement, and 8) at work at entry to the clinic. The effect of lawyer involvement was stronger for patients with less intense pain on initial visit (odds ratio = 2.97; 95% confidence interval, 1.77-4.99). Similarly, the effect of work status was stronger for patients with less intense pain on initial visit (odds ratio = 2.02; 95% confidence interval, 1.18-3.46).
  
  
  CONCLUSIONS
  Researchers and clinicians should be aware of the potential for non-injury-related factors to delay recovery, and be aware of the interaction between the initial intensity of a patient's pain and other covariates when confirming these results.
authors.affiliation: Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada. jdufton@interchange.ubc.ca
authors.forename: John A
authors.initials: JA
authors.lastname: Dufton
authors.forename: Jacek A
authors.initials: JA
authors.lastname: Kopec
authors.forename: Hubert
authors.initials: H
authors.lastname: Wong
authors.forename: J David
authors.initials: JD
authors.lastname: Cassidy
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Quon
authors.forename: Greg
authors.initials: G
authors.lastname: McIntosh
authors.forename: Mieke
authors.initials: M
authors.lastname: Koehoorn
mesh_terms: D000063:Accidents, Traffic / Q000331:legislation & jurisprudence; D000328:Adult; D015331:Cohort Studies; D004185:Disability Evaluation; D004651:Employment; D005260:Female; D006801:Humans; D019458:Insurance Coverage; D008297:Male; D019547:Neck Pain / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D016017:Odds Ratio; D011379:Prognosis; D020127:Recovery of Function; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014911:Whiplash Injuries / Q000150:complications / Q000175:diagnosis* / Q000534:rehabilitation*