title: Stigmata of hemorrhage in bleeding peptic ulcers: an interobserver agreement study among international experts.
abstract: BACKGROUND
  Stigmata of hemorrhage predict rebleeding and outcome of patients with bleeding peptic ulcers. There are variabilities in reported incidences of stigmata and their respective rebleeding risks. We sought to study the interobserver agreement among experts.
  
  
  METHODS
  Between June 1994 and July 1994, 100 consecutive patients with bleeding peptic ulcers underwent videoendoscopy within 24 hours of their admissions. An edited videotape of these ulcers was compiled and sent to an international panel of 14 experts. They independently rated these ulcers exclusively into one of the six categories: spurting, oozing, nonbleeding visible vessel, adherent clot, flat pigmented spot, or clean based. Agreement between any two experts was expressed by a kappa estimate (kappa). Agreements over individual stigmata and a composite kappa estimate (kappa(w)) signifying overall agreement were also computed.
  
  
  RESULTS
  Out of the possible 91 pairwise kappa estimates among 14 experts, 35 (38.5%) were less than or equal to 0.40, indicating poor agreement. None of the kappa estimates was greater than 0.75. Composite kappa estimates for individual stigmata were as follows: spurting kappa = 0.664, oozing kappa = 0.420, nonbleeding visible vessel kappa = 0.342, adherent clot kappa = 0.426, flat pigmented spot kappa = 0.393, and clean-based ulcer kappa = 0.371. The weighted kappa estimate was 0.426.
  
  
  CONCLUSIONS
  Agreement between experts was poor in more than a third of occasions. Although the overall interobserver agreement was fair (0.4 < kappa < 0.75), agreements for nonbleeding visible vessels, flat pigmented spots, and clean-based ulcers were poor.
authors.affiliation: Department of Surgery, Center of Clinical Trials and Epidemiological Research, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin.
authors.forename: J Y
authors.initials: JY
authors.lastname: Lau
authors.forename: J J
authors.initials: JJ
authors.lastname: Sung
authors.forename: A C
authors.initials: AC
authors.lastname: Chan
authors.forename: G W
authors.initials: GW
authors.lastname: Lai
authors.forename: J T
authors.initials: JT
authors.lastname: Lau
authors.forename: E K
authors.initials: EK
authors.lastname: Ng
authors.forename: S C
authors.initials: SC
authors.lastname: Chung
authors.forename: A K
authors.initials: AK
authors.lastname: Li
mesh_terms: D016145:Endoscopy, Digestive System / Q000592:standards / Q000706:statistics & numerical data*; D006801:Humans; D015588:Observer Variation; D010437:Peptic Ulcer / Q000150:complications* / Q000175:diagnosis; D010438:Peptic Ulcer Hemorrhage / Q000175:diagnosis* / Q000209:etiology; D010818:Practice Patterns, Physicians'; D011237:Predictive Value of Tests; D011785:Quality Assurance, Health Care; D012008:Recurrence; D012189:Retrospective Studies; D014741:Video Recording