Statistical Analysis
The coding and statistical analysis of the data were done on the computer, using the SPSS 22 software (IBM SPSS Statistics, IBM Corporation, Chicago, IL) package. Descriptive statistical data for continuous variables were expressed in terms of the mean and median, whereas categorical variables were expressed in terms of frequency and percentages. Receiver operating characteristic curves (ROCs) were created to evaluate the predictive role of the modified S-ReCS, RUSS, and R.I.R.S scoring systems in terms of residual stone presence and postoperative infective complication rates. Univariate and multivariate logistic regression models were used to identify risk factors for residual stones and postoperative infective complications. The statistical significance level was accepted as 0.05 in all analyses.