Validation of the Rockall risk scoring system in upper gastrointestinal bleeding

Background-Several scoring systems have been developed to predict the risk of rebleeding or death in patients with upper gastrointestinal bleeding (UG IB). These risk scoring systems have not been validated in a new patient po pulation outside the clinical context of the original study. Aims-To assess internal and external validity of a simple risk scoring syst em recently developed by Rockall and coworkers. Methods-Calibration and discrimination were assessed as measures of validit y of the scoring system. Internal validity was assessed using an independen t, but similar patient sample studied by Rockall and coworkers, after devel oping the scoring system (Rockall's validation sample). External validity w as assessed using patients admitted to several hospitals in Amsterdam (Vree burg's validation sample). Calibration was evaluated by a chi(2) goodness o f fit test, and discrimination was evaluated by calculating the area under the receiver operating characteristic (ROC) curve. Results-Calibration indicated a poor fit in both validation samples for the prediction of rebleeding (p < 0.0001, Vreeburg; p = 0.007, Rockall), but a better fit for the Amsterdam, The Netherlands prediction of mortality in b oth validation samples (p = 0.2, Vreeburg; p = 0.3, Rockall). The areas und er the ROC curves were rather low in both validation samples for the predic tion of rebleeding (0.61, Vreeburg; 0.70, Rockall), but higher for the pred iction of mortality (0.73, Vreeburg; 0.81, Rockall). Conclusions-The risk scoring system developed by Rockall and coworkers is a clinically useful scoring system for stratifying patients with acute UGIB into high and low risk categories for mortality. For the prediction of rebl eeding, however, the performance of this scoring system was unsatisfactory.