Predicting the outcome of severe ulcerative colitis: development of a novel risk score to aid early selection of patients for second-line medical therapy or surgery

Background: The failure rate of medical therapy in severe ulcerative colitis is high. A risk index, to aid the identification of patients of not responding at an early stage to intravenous corticosteroid therapy, would be useful to facilitate second-line treatment or surgery. Methods: We recruited 167 consecutive patients with severe ulcerative colitis between January 1995 and March 2002; and employed multiple logistic regression to analyse parameters within the first 3 days of medical therapy. We applied statistical modelling to formulate a risk score according to the likelihood of medical failure. Results: Sixty-seven (40%) patients failed to respond to medical therapy. Multiple logistic regression analysis identified mean stool frequency and colonic dilatation within the first 3 days and hypoalbuminaemia as independent predictors of outcome (P < 0.001, 0.001 and 0.002 respectively). A numerical risk score was formulated based on these variables. Patients with scores of 0-1, 2-3 and greater than or equal to4 had a medical therapy failure rate of 11%, 43% and 85% respectively. Receiver-operator characteristic analysis of this score yielded area under curve of 0.88, with a sensitivity of 85% and specificity of 75% using score greater than or equal to4 in predicting non-response. Conclusion: This risk score allows the early identification of patients with severe ulcerative colitis who would be suitable for second-line medical therapy or surgery.