Supplementary Material for: Risk of Postoperative Renal Failure in Radical Nephrectomy and Nephroureterectomy: A Validated Risk Prediction Model

<b><i>Introduction:</i></b> The study aimed to construct and validate a risk prediction model for incidence of postoperative renal failure (PORF) following radical nephrectomy and nephroureterectomy. <b><i>Methods:</i></b> The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database years 2005–2014 were used for the derivation cohort. A stepwise multivariate logistic regression analysis was conducted, and the final model was validated with an independent cohort from the ACS-NSQIP database years 2015–2017. <b><i>Results:</i></b> In cohort of 14,519 patients, 296 (2.0%) developed PORF. The final 9-factor model included age, gender, diabetes, hypertension, BMI, preoperative creatinine, hematocrit, platelet count, and surgical approach. Model receiver-operator curve analysis provided a C-statistic of 0.79 (0.77, 0.82; <i>p</i> &lt; 0.001), and overall calibration testing <i>R</i>² was 0.99. Model performance in the validation cohort provided a C-statistic of 0.79 (0.76, 0.81; <i>p</i> &lt; 0.001). <b><i>Conclusion:</i></b> PORF is a known risk factor for chronic kidney disease and cardiovascular morbidity, and is a common occurrence after unilateral kidney removal. The authors propose a robust and validated risk prediction model to aid in identification of high-risk patients and optimization of perioperative care.

<b><i>引言：</i></b> 本研究旨在构建并验证根治性肾切除术与肾输尿管切除术后术后肾功能衰竭（postoperative renal failure, PORF）的发生风险预测模型。
<b><i>方法：</i></b> 本研究以美国外科医师学会国家外科质量改进计划（American College of Surgeons National Surgical Quality Improvement Program, ACS-NSQIP）2005–2014年的数据库作为推导队列。采用逐步多因素logistic回归分析构建最终预测模型，并使用ACS-NSQIP数据库2015–2017年的独立队列对模型进行外部验证。
<b><i>结果：</i></b> 在纳入的14519例患者队列中，共计296例（2.0%）发生术后肾功能衰竭（PORF）。最终构建的9因素预测模型纳入了年龄、性别、糖尿病史、高血压史、身体质量指数（Body Mass Index, BMI）、术前肌酐水平、血细胞比容、血小板计数及手术入路方式。模型的受试者工作特征曲线（receiver-operator curve, ROC）分析显示，其C统计量为0.79（95%置信区间：0.77, 0.82；*p* < 0.001），整体校准检验的决定系数*R*²为0.99。在验证队列中，该模型的C统计量为0.79（95%置信区间：0.76, 0.81；*p* < 0.001）。
<b><i>结论：</i></b> 术后肾功能衰竭（PORF）是慢性肾脏病与心血管不良事件的已知危险因素，且在单侧肾脏切除术后较为常见。本研究提出了一款经过验证的稳健风险预测模型，可用于识别高危患者并优化围手术期诊疗方案。