A Novel Easy-to-Use Prediction Scheme for Upper Gastrointestinal Bleeding: Cologne-WATCH (C-WATCH) Risk Score

Abstract

Acute upper gastrointestinal bleeding (UGIB) is the leading indication for emergency endoscopy. Scoring schemes have been developed for immediate risk stratification. However, most of these scores include endoscopic findings and are based on data from patients with nonvariceal bleeding. The aim of our study was to design a pre-endoscopic score for acute UGIB--including variceal bleeding--in order to identify high-risk patients requiring urgent clinical management. The scoring system was developed using a data set consisting of 586 patients with acute UGIB. These patients were identified from the emergency department as well as all inpatient services at the University Hospital of Cologne within a 2-year period (01/2007-12/2008). Further data from a cohort of 322 patients who presented to our endoscopy unit with acute UGIB in 2009 served for external/temporal validation.Clinical, laboratory, and endoscopic parameters, as well as further data on medical history and medication were retrospectively collected from the electronic clinical documentation system. A multivariable logistic regression was fitted to the development set to obtain a risk score using recurrent bleeding, need for intervention (angiography, surgery), or death within 30 days as a composite endpoint. Finally, the obtained risk score was evaluated on the validation set. Only C-reactive protein, white blood cells, alanine-aminotransferase, thrombocytes, creatinine, and hemoglobin were identified as significant predictors for the composite endpoint. Based on the regression coefficients of these variables, an easy-to-use point scoring scheme (C-WATCH) was derived to estimate the risk of complications from 3% to 86% with an area under the curve (AUC) of 0.723 in the development set and 0.704 in the validation set. In the validation set, no patient in the identified low-risk group (0-1 points), but 38.7% of patients in the high-risk group (≥ 2 points) reached the composite endpoint. Our easy-to-use scoring scheme is able to distinguish high-risk patients requiring urgent endoscopy, from low-risk cases who are suitable candidates for outpatient management or in whom endoscopy may be postponed. Based on our findings, a prospective validation of the C-WATCH score in different patient populations outside the university hospital setting seems warranted.

FIGURE 1

C-WATCH score scheme of the 7 steps for calculating the C-WATCH score.

FIGURE 2

Area under ROC curve discrimination between patients with complication (yes/no) in the development set (A: C-WATCH model, area under ROC curve 0.739, and C-WATCH score, AUC 0.723) and the validation set (B: AUC 0.700 and 0.704, respectively). Calibration plots of both models (white points) and risk score (black points) in the development set (C) and validation set (D). Whiskers denote 95% confidence intervals (Clopper–Pearson). ROC = receiver operating characteristic.