Amnon Sonnenberg1. 1. The Portland VA Medical Center and the Division of Gastroenterology/Hepatology, Oregon Health & Science University, Portland, USA.
Abstract
BACKGROUND AND AIMS: The search for a source of gastrointestinal bleeding is associated with two distinct approaches of trying to rule in a specific diagnosis or rule out any potential source of bleeding. The study aim was to understand the conceptual differences underlying the two searches. METHODS: The performance of endoscopy as diagnostic test is analyzed in terms of Bayes' formula. RESULTS: The performance of gastrointestinal endoscopy to rule in a suspected lesion is mostly influenced by its underlying specificity. Because the specificity of endoscopy is less likely to be affected by procedural exigencies, the demands on pre-procedural prep and general quality can be more relaxed. In contradistinction, the performance of endoscopy to rule out a suspected bleeding site is mostly influenced by its sensitivity, which can easily be compromised by suboptimal procedural conditions. CONCLUSIONS: Paradoxically, the more urgent, focused, and important search (to rule in a bleeding site), carries less stringent criteria for its execution than the more general and aimless search (to rule out a bleeding site) that frequently ends up just empty handed.
BACKGROUND AND AIMS: The search for a source of gastrointestinal bleeding is associated with two distinct approaches of trying to rule in a specific diagnosis or rule out any potential source of bleeding. The study aim was to understand the conceptual differences underlying the two searches. METHODS: The performance of endoscopy as diagnostic test is analyzed in terms of Bayes' formula. RESULTS: The performance of gastrointestinal endoscopy to rule in a suspected lesion is mostly influenced by its underlying specificity. Because the specificity of endoscopy is less likely to be affected by procedural exigencies, the demands on pre-procedural prep and general quality can be more relaxed. In contradistinction, the performance of endoscopy to rule out a suspected bleeding site is mostly influenced by its sensitivity, which can easily be compromised by suboptimal procedural conditions. CONCLUSIONS: Paradoxically, the more urgent, focused, and important search (to rule in a bleeding site), carries less stringent criteria for its execution than the more general and aimless search (to rule out a bleeding site) that frequently ends up just empty handed.
Entities:
Keywords:
Bayes’ formula; gastrointestinal bleeding; gastrointestinal endoscopy; medical decision analysis; outcome research
Authors: Ian Mark Gralnek; Ori Segol; Alain Suissa; Peter D Siersema; David L Carr-Locke; Zamir Halpern; Erwin Santo; Svetlana Domanov Journal: Endoscopy Date: 2013-08-12 Impact factor: 10.093