title: External validation of a clinical prediction rule to predict full recovery and ongoing moderate/severe disability following acute whiplash injury.
abstract: METHODS
  Retrospective secondary analysis of data.
  
  
  OBJECTIVE
  To investigate the external validity of the whiplash clinical prediction rule (CPR).
  
  
  BACKGROUND
  We recently derived a whiplash CPR to consolidate previously established prognostic factors for poor recovery from a whiplash injury and predicted 2 recovery pathways. Prognostic factors for full recovery were being less than 35 years of age and having an initial Neck Disability Index (NDI) score of 32% or less. Prognostic factors for ongoing moderate/severe pain and disability were being 35 years of age or older, having an initial NDI score of 40% or more, and the presence of hyperarousal symptoms. Validation is required to confirm the reproducibility and accuracy of this CPR. Clinician feedback on the usefulness of the CPR is also important to gauge acceptability.
  
  
  METHODS
  A secondary analysis of data from 101 individuals with acute whiplash-associated disorder who had previously participated in either a randomized controlled clinical trial or prospective cohort study was performed using accuracy statistics. Full recovery was defined as NDI score at 6 months of 10% or less, and ongoing moderate/severe pain and disability were defined as an NDI score at 6 months of 30% or greater. In addition, a small sample of physical therapists completed an anonymous survey on the clinical acceptability and usability of the tool. Results The positive predictive value of ongoing moderate/severe pain and disability was 90.9% in the validation cohort, and the positive predictive value of full recovery was 80.0%. Surveyed physical therapists reported that the whiplash CPR was simple, understandable, would be easy to use, and was an acceptable prognostic tool.
  
  
  CONCLUSIONS
  External validation of the whiplash CPR confirmed the reproducibility and accuracy of this dual-pathway tool for individuals with acute whiplash-associated disorder. Further research is needed to assess prospective validation, the impact of inclusion on practice, and to examine the efficacy of linking treatment strategies with predicted prognosis.
  
  
  METHODS
  Prognosis, level 1b.
authors.affiliation: Menzies Health Institute Queensland, Centre for National Research on Disability and Rehabilitation Medicine (CONROD), Griffith University, Gold Coast, Australia.
authors.forename: Carrie
authors.initials: C
authors.lastname: Ritchie
authors.forename: Joan
authors.initials: J
authors.lastname: Hendrikz
authors.forename: Gwendolen
authors.initials: G
authors.lastname: Jull
authors.forename: James
authors.initials: J
authors.lastname: Elliott
authors.forename: Michele
authors.initials: M
authors.lastname: Sterling
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D003661:Decision Support Techniques; D004185:Disability Evaluation; D005246:Feedback; D006801:Humans; D008875:Middle Aged; D019547:Neck Pain / Q000209:etiology; D059825:Physical Therapists; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015599:Trauma Severity Indices; D014911:Whiplash Injuries / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D055815:Young Adult
keywords: Neck Disability Index; prediction; prognosis; whiplash-associated disorder