Consensus-based development of a causal attribution system for post-ERCP adverse events

No tool currently exists to help practitioners and researchers attribute causality of adverse events (AEs) to antecedent endoscopic retrograde cholangiopancreatography (ERCP) procedures. After three rounds of iterative feedback from 15 international ERCP experts using the RAND/University of California, Los Angeles Appropriateness Method, definitions and relatedness criteria were drafted for pancreatitis, bleeding, perforation, cholangitis, cholecystitis, abdominal pain and non-gastrointestinal AEs. Inter-panellist agreement was high for all definitions and criteria at the end of the third round. Possible outcomes for relatedness were definite, probable, possible, unlikely, unrelated or unclassifiable. This novel system bridges the gap in attributing causality to an antecedent AE and will serve as a schema for clinical quality assurance and for outcomes-based research.