title: Regression tree for choledocholithiasis prediction.
abstract: OBJECTIVE
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: aDepartment of Urology, Clinic of Urology and Nephrology, Clinical Centre 'Kragujevac', Kragujevac bDepartment of Surgery, General Hospital Gornji Milanovac, Gornji Milanovac, Serbia.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Stojadinovic M
authors.forename: Tomislav
authors.initials: T
authors.lastname: Pejovic
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000097:blood; D017081:Cholecystectomy, Laparoscopic; D042883:Choledocholithiasis / Q000097:blood / Q000175:diagnosis*; D003549:Cystic Duct / Q000473:pathology*; D005260:Female; D042882:Gallstones / Q000601:surgery*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009929:Organ Size; D011237:Predictive Value of Tests; D055815:Young Adult
chemical_list: D000469:Alkaline Phosphatase