title: Evaluating the endoscopic reference score for eosinophilic esophagitis: moderate to substantial intra- and interobserver reliability.
abstract: OBJECTIVE
  Recently the Endoscopic Reference Score (EREFS) for endoscopic assessment of eosinophilic esophagitis was introduced, with good interobserver agreement for most signs. The EREFS has not yet been evaluated by other investigators and intraobserver agreement has not been assessed. The aim of this study was to further validate the EREFS by assessing interobserver and intraobserver agreement of endoscopic signs in patients with eosinophilic esophagitis.
  
  
  METHODS
  High-quality endoscopic images were made of the esophagus of 30 patients with eosinophilic esophagitis (age 36 years, range 23 - 46 years; 5 female), 6 of whom were in remission. At least three depersonalized images per patient were incorporated into a slideshow. Images were scored by four expert and four trainee endoscopists who were blinded to the patients' conditions. Interobserver agreement was assessed. After 4 weeks, the images were rescored in a different order to assess intraobserver agreement.
  
  
  RESULTS
  Interobserver agreement was substantial for rings (κ 0.70), white exudates (κ 0.63), and crepe paper esophagus (κ 0.62), moderate for furrows (κ 0.49) and strictures (κ 0.54), and slight for edema (κ 0.12). Intraobserver agreement was substantial for rings (median κ 0.64, IQR 0.46 - 0.70), furrows (median κ 0.69, IQR 0.50 - 0.89), and crepe paper esophagus (median κ 0.69, IQR 0.62 - 0.83), moderate for white exudates (median κ 0.58, IQR 0.54 - 0.71) and strictures (median κ 0.54, IQR 0.33 - 0.70), and less than chance for edema (median κ 0.00, IQR 0.00 - 0.29). Inter- and intraobserver agreement was not substantially different between expert and trainee endoscopists.
  
  
  CONCLUSIONS
  Using the EREFS, endoscopic signs of eosinophilic esophagitis were scored consistently by expert and trainee endoscopists.
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Bram D
authors.initials: BD
authors.lastname: van Rhijn
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Marijn J
authors.initials: MJ
authors.lastname: Warners
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Wouter L
authors.initials: WL
authors.lastname: Curvers
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Anja U
authors.initials: AU
authors.lastname: van Lent
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Noor L
authors.initials: NL
authors.lastname: Bekkali
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: R Bart
authors.initials: RB
authors.lastname: Takkenberg
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Jaap J
authors.initials: JJ
authors.lastname: Kloek
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Jacques J G H M
authors.initials: JJ
authors.lastname: Bergman
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Fockens
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Bredenoord
mesh_terms: D000328:Adult; D057765:Eosinophilic Esophagitis / Q000175:diagnosis*; D004945:Esophagoscopy / Q000379:methods*; D004947:Esophagus / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D055815:Young Adult