Regression tree for choledocholithiasis prediction

Objectives The aim of this study was to develop and compare the predictive accuracy of classification and regression tree (CART) analysis with logistic regression (LR) for predicting common bile duct stones (CBDS) in patients subjected to laparoscopic cholecystectomy. Patients and methods We prospectively collected preoperative (demographic, biochemical, ultrasonographic) and intraoperative (intraoperative cholangiography, cystic duct diameter) data for 154 patients considered for elective laparoscopic cholecystectomy at the department of General Surgery at Gornji Milanovac from 2013 through 2014. Univariate and multivariate regression analyses were used to determine independent predictors of CBDS. The CART analysis was carried out using the predictors identified by LR analysis. Various measures for the assessment of risk prediction models were determined, such as predictive ability, accuracy, the area under the receiver operating characteristic curve, and clinical utility using decision curve analysis. Results The most decisive variable at the time of classification was the cystic duct diameter category, the alkaline phosphatase, and dangerous stones. The CART model was shown to have good discriminatory ability (93.9%). Accuracy was similar in both models, ranging from 92.9% in the CART model and 93.5% in the LR model. In decision curve analysis, the CART model outperformed the LR model. Conclusion We developed a user-friendly risk model that can successfully predict the presence of choledocholithiasis in patients planned for elective cholecystectomy. However, before recommending its use in clinical practice, a larger and more complete database should be used to further clarify the differences between models in terms of prediction of the CBDS. Copyright (C) 2015 Wolters Kluwer Health, Inc. All rights reserved.