title: Grading of dysplasia in Barrett's oesophagus: substantial interobserver variation between general and gastrointestinal pathologists.
abstract: OBJECTIVE
  To determine interobserver variation in grading of dysplasia in Barrett's oesophagus (BO) between non-expert general pathologists and expert gastrointestinal pathologists on the one hand and between expert pathologists on the other hand.
  
  
  RESULTS
  In this prospective multicentre study, non-expert and expert pathologists graded biopsy specimens of 920 patients with endoscopic BO, which were blindly reviewed by one member of a panel of expert pathologists (panel experts) and by a second panel expert in case of disagreement on dysplasia grade. Agreement between two of three pathologists was established as the final diagnosis. Analysis was performed by kappa statistics. Due to absence of intestinal metaplasia, 127/920 (14%) patients were excluded. The interobserver agreement for dysplasia [no dysplasia (ND) versus indefinite for dysplasia/low-grade dysplasia (IND/LGD) versus high-grade dysplasia (HGD)/adenocarcinoma (AC)] between non-experts and first panel experts and between initial experts and first panel experts was fair (kappa = 0.24 and kappa = 0.27, respectively), and substantial for differentiation of HGD/AC from ND/IND/LGD (kappa = 0.62 and kappa = 0.58, respectively).
  
  
  CONCLUSIONS
  There was considerable interobserver variability in the interpretation of ND or IND/LGD in BO between non-experts and experts, but also between expert pathologists. This suggests that less subjective markers are needed to determine the risk of developing AC in BO.
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Centre Rotterdam, Rotterdam, The Netherlands. m.kerkhof@erasmusmc.nl
authors.forename: M
authors.initials: M
authors.lastname: Kerkhof
authors.forename: H
authors.initials: H
authors.lastname: van Dekken
authors.forename: E W
authors.initials: EW
authors.lastname: Steyerberg
authors.forename: G A
authors.initials: GA
authors.lastname: Meijer
authors.forename: A H
authors.initials: AH
authors.lastname: Mulder
authors.forename: A
authors.initials: A
authors.lastname: de Bruïne
authors.forename: A
authors.initials: A
authors.lastname: Driessen
authors.forename: F J
authors.initials: FJ
authors.lastname: ten Kate
authors.forename: J G
authors.initials: JG
authors.lastname: Kusters
authors.forename: E J
authors.initials: EJ
authors.lastname: Kuipers
authors.forename: P D
authors.initials: PD
authors.lastname: Siersema
mesh_terms: D000230:Adenocarcinoma / Q000145:classification / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001471:Barrett Esophagus / Q000145:classification / Q000175:diagnosis*; D004938:Esophageal Neoplasms / Q000145:classification / Q000175:diagnosis*; D005104:Expert Testimony; D005260:Female; D005762:Gastroenterology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D015588:Observer Variation; D010336:Pathology; D011230:Precancerous Conditions / Q000145:classification / Q000175:diagnosis*; D011446:Prospective Studies; D016037:Single-Blind Method