Establishment and validation of a predictive model for the efficacy of repeated extracorporeal shock wave lithotripsy in patients with upper urinary calculi / 现代泌尿外科杂志

ABSTRACT

【Objective】 To analyze the independent influencing factors of repeated extracorporeal shock wave lithotripsy (ESWL) in the treatment of upper urinary calculi (UUC), based on which a nomogram model was established to predict the efficacy. 【Methods】 Clinical and imaging data of 203 patients receiving repeated ESWL during Jan.2020 and Dec.2022 were collected, including 117 cases in the successful group and 86 cases in the unsuccessful group.The patients’ age and sex, stone volume (SV), surface area (SA), skin-to-site distance (SSD), maximum CT value, mean stone density (MSD), and stone heterogeneity index (SHI) were compared between the two groups.The independent predictors were analyzed with logistic regression and the meaningful variables (P<0.05) were used to establish a nomogram.The efficacy of the model was evaluated using receiver operating characteristic (ROC) curve and decreasing curve analysis (DCA).Internal validation was also performed. 【Results】 Stepwise regression showed that SV, SSD, MSD and SHI were independent influencing factors (P<0.05).The area under the ROC curve (AUC), optimal threshold, sensitivity and specificity were 0.793 (95%CI 0.674-0.911), 0.619, 77.1% and 74.0%, respectively.The DCA curve was above two extreme curves.Hosmer-Lemeshow test and calibration curve showed that the nomogram had a good fitting degree (χ2=5.526, P=0.489), and the correction C-index was 0.746. 【Conclusion】 SV, SSD, MSD and SHI are independent predictors of the efficacy of repeated ESWL in the treatment of UUC.The nomogram established based on the above indicators has good predictive efficiency and clinical applicability.