The risk of disabling, surgery and reoperation in Crohn’s disease – A decision tree-based approach to prognosis

Claudia Camila Dias1,2, Pedro Pereira Rodrigues1,2, Fernando Magro3,4,5

1Department of Community Medicine, Information and Decision in Health, Faculty of Medicine of the University of Porto, Porto, Portugal, 2CINTESIS – Center for Health Tecnology and Services Research, Porto, Portugal, 3Gastroenterology Department, Hospital São João, Porto, Portugal, 4Institute of Pharmacology and Therapeutics Faculty of Medicine of the University of Porto, Porto, Portugal, 5MedInUP – Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal

Crohn’s disease (CD) is a chronic inflammatory bowel disease known to carry a high risk of disabling and many times requiring surgical interventions.

This multicentric study involved 1547 CD patients retrospectively enrolled and divided into two cohorts: a derivation one (80%) and a validation one (20%). Decision trees were built upon applying the CHAID algorithm for the selection of variables.

Three-level decision trees were built for the risk of disabling and reoperation, whereas the risk of surgery was described in a two-level one. A receiver operating characteristic (ROC) analysis was performed, and the area under the curves (AUC) Was higher than 70% for all outcomes. The defined risk cut-off values show usefulness for the assessed outcomes: risk levels above 75% for disabling had an odds test positivity of 4.06 [3.50–4.71], whereas risk levels below 34% and 19% excluded surgery and reoperation with an odds test negativity of 0.15 [0.09–0.25] and 0.50 [0.24–1.01], respectively. Overall, patients with B2 or B3 pheno- type had a higher proportion of disabling disease and surgery, while patients with later introduction of pharmacological therapeutic (1 months after initial surgery) had a higher pro- portion of reoperation.

The decision-tree based approach used in this study, with demographic and clinical vari- ables, has shown to be a valid and useful approach to depict such risks of disabling, surgery and reoperation.

keywords: Decision Tree, Crohn disease, disabling disease, reoperation

Poster: The risk of disabling, surgery and reoperation in Crohn’s disease – a decision tree-based approach to prognosis