A Novel Tool To Predict The One-year Risk Of Abdominal Surgery In Crohn’s Disease: The Imaging Severity Index

ObjectiveIt is not unusual for CD patients to undergo abdominal surgery. Predicting the need for surgery is therefore important in the planning of treatment for these patients. There is a need for a scoring tool that provides an assessment of bowel damage and predicts surgical requirement. The aim was to propose a practical index and evaluate its adequacy in predicting the one-year risk of abdominal surgery in patients with CD.MethodsA single center retrospective study of patients with CD from Jan 2013 to Jan 2015 was conducted. Patients were followed until surgery or for at least one year. Clinical characteristics were analyzed. The Imaging Severity Index was calculated taking into account damage location, severity, extent, as measured by diagnostic imaging modalities. The validation of the Imaging Severity Index in predicting the risk of surgery was evaluated.Results307 patients with CD were involved in the study.91 patients underwent abdominal surgery. The Imaging Severity Index was much higher in patients with surgery (52.5) than those without surgery (20.9) (p<0.001). On tertiles of the Imaging Severity Index, the frequency of surgery grew (2.9%,17.6%, and 68.0%) as the Imaging Severity Index increased. The ROC curve was constructed to predict one-year risk of surgery, and the area under ROC was 0.885.35.25 was used as the cut-off value with a sensitivity of 80.2%, specificity of 83.8%. Patients with the Imaging Severity Index≥35.25 carried a higher risk of abdominal surgery (OR=18.99).ConclusionsThe Imaging Severity Index is a reliable index to predict one-year risk of abdominal surgery. Patients with the Imaging Severity Index≥ 35.25 carry a higher risk of surgery within one year and need closer follow-up or step-up therapy.