关键词: 肾结石, 风险预测模型, 列线图, 高钙尿症, 术后泌尿系统感染, 预后营养指数

Abstract: Objective To identify the key factors associated with the postoperative recurrence of nephrolithiasis in patients from the Linfen region and to construct a nomogram for predicting recurrence risk, thereby providing a basis for regionalized prevention and treatment strategies. Methods A cohort of patients with nephrolithiasis who underwent minimally invasive surgery at Linfen People's Hospital between January 2022 and October 2023 was prospectively studied. All participants were followed for one year postoperatively to monitor for disease recurrence. Data including general patient characteristics, preoperative laboratory results, and surgical variables were collected. Lasso and Cox regression analyses were employed to screen for significant risk factors for nephrolithiasis recurrence. Subsequently, a nomogram was developed using R software based on the identified factors. The predictive performance and clinical utility of the model were evaluated using the concordance index (C-index), calibration curves, and decision curve analysis. Results This study initially enrolled 480 patients with nephrolithiasis, of whom 469 completed the one-year follow-up. During the follow-up period, 91 patients experienced recurrence, yielding a recurrence rate of 19.40%. Lasso and Cox regression analyses identified the following independent risk factors for recurrence: comorbid diabetes mellitus (HR=1.769), comorbid hypercalciuria (HR=2.456), frequency of noodles consumption (HR=1.933), daily water intake (HR=1.611), primary type of drinking water (HR=2.667), postoperative urinary tract infection (HR=2.231), preoperative osteopontin levels (HR=1.972), and preoperative prognostic nutritional index (HR=2.849). The nomogram, based on the Cox regression model, demonstrated good discrimination with a C-index of 0.824. The calibration curve indicated no statistically significant deviation between the predicted probabilities and actual observations (c²=11.826, P=0.159), suggesting excellent model fit. Decision curve analysis revealed that the model offered a positive net benefit within the risk threshold probability ranges of 0.01-0.65 and 0.78-0.99, with a maximum net benefit of 0.186. Conclusions This study successfully identified key risk factors for the postoperative recurrence of nephrolithiasis in the Linfen population. The constructed nomogram demonstrated robust discrimination and calibration. The positive net benefit within specific risk thresholds indicates its clinical utility, providing a precise and practical tool for guiding regionalized strategies for the prevention and management of nephrolithiasis recurrence.

Key words: Nephrolithiasis, Risk prediction model, Nomogram, Hypercalciuria, Postoperative urinary tract infection, Prognostic Nutritional Index