title: CT grading scales for splenic injury: why can't we agree?
abstract: BACKGROUND
  Computed tomography (CT) has been proven to be able to accurately diagnose splenic injury. Many have published CT splenic injury grading scales to quantify the extent of injury. However, these scales have failed at predicting clinical outcomes and therefore cannot be used to accurately predict the need for intervention. We hypothesised that low interrater reliability is the reason why these scales have failed at predicting clinical outcomes.
  
  
  METHODS
  This is a retrospective study of patients who were admitted to the Royal Perth Hospital with blunt splenic injury as coded in the trauma registry. The abdominal CT images of these patients were reviewed by three consultant radiologists and were graded using the six different splenic injury grading scales. We assessed interrater reliability between each of the scales using generalised kappa and proportion of agreement calculations.
  
  
  RESULTS
  The images of 64 patients were reviewed. The interrater reliability yielded a generalised kappa score of 0.32-0.60 and proportion of agreement ranging from 34.4% to 65.5%.
  
  
  CONCLUSIONS
  The six studied CT splenic injury grading scales did not have a high enough interrater reliability to be adequate for clinical use. The poor interrater reliability is likely to contribute to the failure of the scales at predicting clinical outcomes. Further research to improve the interrater reliability is recommended.
authors.affiliation: University of Notre Dame Australia, School of Medicine, Fremantle, Western Australia, Australia. rhys.clark@gmail.com
authors.forename: Rhys
authors.initials: R
authors.lastname: Clark
authors.forename: Kathryn
authors.initials: K
authors.lastname: Hird
authors.forename: Philip
authors.initials: P
authors.lastname: Misur
authors.forename: Duncan
authors.initials: D
authors.lastname: Ramsay
authors.forename: Richard
authors.initials: R
authors.lastname: Mendelson
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013154:Spleen / Q000000981:diagnostic imaging* / Q000293:injuries* / Q000601:surgery; D013156:Splenectomy; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014949:Wounds, Nonpenetrating / Q000000981:diagnostic imaging* / Q000601:surgery