STIGMATA OF HEMORRHAGE IN BLEEDING PEPTIC-ULCERS - AN INTEROBSERVER AGREEMENT STUDY AMONG INTERNATIONAL EXPERTS

Background: Stigmata of hemorrhage predict rebleeding and outcome of p atients with bleeding peptic ulcers. There are variabilities in report ed incidences of stigmata and their respective rebleeding risks. We so ught to study the interobserver agreement among experts. Methods: Betw een June 1994 and July 1994, 100 consecutive patients with bleeding pe ptic ulcers underwent videoendoscopy within 24 hours of their admissio ns. An edited videotape of these ulcers was compiled and sent to an in ternational panel of 14 experts. They independently rated these ulcers exclusively into one of the six categories: spurting, oozing, nonblee ding visible vessel, adherent clot, flat pigmented spot, or clean base d. Agreement between any two experts was expressed by a kappa estimate (kappa). Agreements over individual stigmata and a composite kappa es timate (kappa(w),) signifying overall agreement were also computed. Re sults: Out of the possible 91 pairwise kappa estimates among 14 expert s, 35 (38.5%) were less than or equal to 0.40, indicating poor agreeme nt. 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 cl ean-based ulcer kappa = 0.371. The weighted kappa estimate was 0.426. Conclusion: 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 pig mented spots, and clean-based ulcers were poor.