Supplementary Material for: RHEMITT Score: Predicting the Risk of Rebleeding for Patients with Mid-Gastrointestinal Bleeding Submitted to Small Bowel Capsule Endoscopy

Introduction: Small bowel capsule endoscopy (SBCE) is the gold standard for mid-gastrointestinal bleeding (MGIB). No score has been developed to predict the risk of small bowel rebleeding after SBCE. Objective: Creating a predictive small bowel rebleeding risk score for MGIB, after initial SBCE. Methods: Retrospective, single center study, including SBCEs for MGIB, from June 2006 to October 2016. The minimum follow-up was 12 months. Univariate analysis and a multivariable Cox regression model tested the association with rebleeding. Statistically significant variables were used to compute the score. The score’s accuracy was tested through a receiver operating characteristic (ROC) curve. A classification tree identified risk groups. For internal validation, we performed a 5-fold cross validation. Results: We assessed 357 SBCEs for MGIB, of which 88 (24.6%) presented rebleeding during follow-up. Seven variables were used to compute a risk-predicting score – the RHEMITT score – namely, renal disease; heart failure; endoscopic capsule P1/P2 lesions; major bleeding; incomplete capsule; tobacco consumption; and endoscopic treatment. The score presented good accuracy toward the outcome (area under the curve ROC 0.842, 95% CI 0.757–0.927). We established 3 rebleeding risk groups: low (0–3 points); intermediate (4–10 points); and high (+11 points). Conclusion: A new MGIB score, named RHEMITT, accurately anticipates the individual risk of small bowel rebleeding after initial SBCE.