Risk matrix model for prediction of colectomy in a population-based study of ulcerative colitis patients (the IBSEN study)

Abstract
Objectives: Identifying ulcerative colitis (UC) patients with increased risk of colectomy is essential for appropriate treatment. We aimed to develop a prediction model assessing the risk of having colectomy within the first 10 years after diagnosis. Material and methods. A population-based inception cohort of UC patients diagnosed in south-eastern Norway between 1990 and 1994 has been followed for 10 years. Altogether 519 patients were recruited including 49 patients who were colectomized. Based on the best-fitted multivariate model, the probabilities of colectomy were computed for selected levels of baseline covariates, and the results arranged in a prediction matrix. The following risk factors at diagnosis were analyzed: age, smoking, sex, disease extent, weight loss and fever and need for systemic steroids. Biochemical markers included C-reactive protein (CRP, Results. Extent of disease, age (Conclusions. Our prediction model revealed significant differences in the probability of undergoing colectomy during a 10-years course of disease, which supports an early individualized treatment approach in UC.