a. Variable(s) entered on step: Preoperative urine
culture, Stone burden, Stone density, Preoperative pelvis urine density,
Stone localization, Preoperative hydronephrosis
Figure 1. Bacteriological analysis of preoperative urine and
intraoperative pelvis culture
Figure 2: Receiver operating characteristic (ROC) curve plot of
pelvis urine density in predicting pelvis culture positivity (AUC:
0.858)