Nomogram Model for Predicting Clinical Efficacy of Emergency Extracorporeal Shock Wave Lithotripsy in Patients with Upper Urinary Tract Calculi: A Single-Centre Retrospective Study

Background and Aims: To explore the factors influencing the clinical efficacy of emergency extracorporeal shock wave lithotripsy (ESWL) in patients with upper urinary tract calculi, construct a nomogram model for predicting stone expulsion outcomes and validate its performance. Methods: A retrospective analysis was conducted on the clinical data of 502 patients with upper urinary tract calculi who underwent emergency ESWL at The First Affiliated Hospital of Henan University of Science and Technology from January 2022 to December 2024. All patients were divided into the effective and ineffective groups based on the complete elimination of calculi within 4 weeks after surgery. Differences in general clinical data, urinalysis, liver and renal function indicators, calculus-related characteristics and treatment-related characteristics between the two groups were compared. Multivariate logistic regression was used to identify independent predictors of ESWL efficacy and construct a nomogram model. The model was evaluated using the receiver operating characteristic curve, calibration curve and decision curve analysis. Results: A total of 140 (27.9%) patients had ineffective treatment. Independent risk factors for failure included long emergency visit-to-ESWL time, high urinary white-blood-cell count, elevated serum creatinine/serum uric acid, large maximum stone diameter, high stone density and severe hydronephrosis; ESWL energy and the number of shocks were mediated associated factors; High estimated glomerular filtration rate and ureteral calculi were protective factors (all p < 0.05). The nomogram showed a good predictive performance (area under the curve = 0.862, 95% confidence interval: 0.793–0.931) with good calibration and net benefit. Conclusions: A validated nomogram based on independent predictors and mediated factors was constructed to provide a reliable tool for emergency ESWL decision-making.