title: Observer agreement in the grading of oral epithelial dysplasia.
abstract: OBJECTIVE
  To determine the extent of observer agreement in diagnosis of oral epithelial dysplasia (OED). Published studies of OED examiner agreement report relatively low agreement levels; however, these studies were limited by the methodologies employed.
  
  
  METHODS
  For this study, 64 slides were each independently examined twice by three oral pathologists. Consistency was assessed by determining intra- and interexaminer agreement. Conformity was assessed by using the modal diagnosis as a gold standard.
  
  
  RESULTS
  The group showed moderate interobserver agreement when grading the presence or absence of OED with a group-simple kappa (Ks) of 0.51 (95% CI = 0.42-0.61), and substantial agreement when using a 5-point ordinal scale with a group-weighted kappa (Kw) of 0.74 (95% CI = 0.64-0.85). The group showed fair to substantial intraexaminer agreement when assessing the presence or absence of OED, with Ks ranging from 0.22 to 0.78, and showing almost a perfect agreement using a 5-point ordinal scale, with Kw ranging from 0.82-0.96. Conformity with the comparison standard modal diagnosis was almost perfect, with pairwise Kw ranging from 0.81 to 0.92.
  
  
  CONCLUSIONS
  Overall, there was substantial intra- and interobserver consistency and almost perfect conformity in the grading of OED. Appropriate statistical methods are necessary to determine the degree of observer agreement.
authors.affiliation: Community Dentistry, Faculty of Dentistry, University of Manitoba, Manitoba, Canada. brothwel@ms.umanitoba.ca
authors.forename: D J
authors.initials: DJ
authors.lastname: Brothwell
authors.forename: D W
authors.initials: DW
authors.lastname: Lewis
authors.forename: G
authors.initials: G
authors.lastname: Bradley
authors.forename: I
authors.initials: I
authors.lastname: Leong
authors.forename: R C K
authors.initials: RC
authors.lastname: Jordan
authors.forename: D
authors.initials: D
authors.lastname: Mock
authors.forename: J L
authors.initials: JL
authors.lastname: Leake
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002278:Carcinoma in Situ / Q000175:diagnosis / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000473:pathology; D015588:Observer Variation; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000473:pathology; D015203:Reproducibility of Results