title: Training improves interobserver reliability for the diagnosis of scaphoid fracture displacement.
abstract: BACKGROUND
  The diagnosis of displacement in scaphoid fractures is notorious for poor interobserver reliability.
  
  
  OBJECTIVE
  We tested whether training can improve interobserver reliability and sensitivity, specificity, and accuracy for the diagnosis of scaphoid fracture displacement on radiographs and CT scans.
  
  
  METHODS
  Sixty-four orthopaedic surgeons rated a set of radiographs and CT scans of 10 displaced and 10 nondisplaced scaphoid fractures for the presence of displacement, using a web-based rating application. Before rating, observers were randomized to a training group (34 observers) and a nontraining group (30 observers). The training group received an online training module before the rating session, and the nontraining group did not. Interobserver reliability for training and nontraining was assessed by Siegel's multirater kappa and the Z-test was used to test for significance.
  
  
  RESULTS
  There was a small, but significant difference in the interobserver reliability for displacement ratings in favor of the training group compared with the nontraining group. Ratings of radiographs and CT scans combined resulted in moderate agreement for both groups. The average sensitivity, specificity, and accuracy of diagnosing displacement of scaphoid fractures were, respectively, 83%, 85%, and 84% for the nontraining group and 87%, 86%, and 87% for the training group. Assuming a 5% prevalence of fracture displacement, the positive predictive value was 0.23 in the nontraining group and 0.25 in the training group. The negative predictive value was 0.99 in both groups.
  
  
  CONCLUSIONS
  Our results suggest training can improve interobserver reliability and sensitivity, specificity and accuracy for the diagnosis of scaphoid fracture displacement, but the improvements are slight. These findings are encouraging for future research regarding interobserver variation and how to reduce it further.
authors.affiliation: Orthopaedic Research Center Amsterdam, Department of Orthopaedic Surgery, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: Geert A
authors.initials: GA
authors.lastname: Buijze
authors.forename: Thierry G
authors.initials: TG
authors.lastname: Guitton
authors.forename: C Niek
authors.initials: CN
authors.lastname: van Dijk
authors.forename: David
authors.initials: D
authors.lastname: Ring
mesh_terms: D002983:Clinical Competence; D003194:Computer-Assisted Instruction; D003951:Diagnostic Errors / Q000517:prevention & control*; D004502:Education, Medical, Continuing / Q000379:methods*; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006801:Humans; D020407:Internet; D008297:Male; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D021361:Scaphoid Bone / Q000000981:diagnostic imaging* / Q000293:injuries; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed