Department of renal medicine, Salford Royal NHS Foundation Trust, Stott Lane, Salford, M6 8HD, UK.
Division of Cardiovascular Sciences, University of Manchester, Manchester, M13 9PL, UK.
BMC Nephrol. 2021 May 24;22(1):194. doi: 10.1186/s12882-021-02402-1.
The Kidney Failure Risk Equation (KFRE) predicts the 2- and 5-year risk of end-stage renal disease (ESRD) in patients with chronic kidney disease (CKD) stages 3a-5. Its predictive performance in advanced CKD and in specific disease aetiologies requires further exploration. This study validates the 4- and 8-variable KFREs in an advanced CKD population in the United Kingdom by evaluating discrimination, calibration and clinical utility.
Patients enrolled in the Salford Kidney Study who were referred to the Advanced Kidney Care Service (AKCS) clinic at Salford Royal NHS Foundation Trust between 2011 and 2018 were included. The 4- and 8-variable KFREs were calculated on the first AKCS visit and the observed events of ESRD (dialysis or pre-emptive transplantation) within 2- and 5-years were the primary outcome. The area under the receiver operator characteristic curve (AUC) and calibration plots were used to evaluate discrimination and calibration respectively in the whole cohort and in specific disease aetiologies: diabetic nephropathy, hypertensive nephropathy, glomerulonephritis, autosomal dominant polycystic kidney disease (ADPKD) and other diseases. Clinical utility was assessed with decision curve analyses, comparing the net benefit of using the KFREs against estimated glomerular filtration rate (eGFR) cut-offs of < 20 ml/min/1.73m and < 15 ml/min/1.73m to guide further treatment.
A total of 743 patients comprised the 2-year analysis and 613 patients were in the 5-year analysis. Discrimination was good in the whole cohort: the 4-variable KFRE had an AUC of 0.796 (95% confidence interval [CI] 0.762-0.831) for predicting ESRD at 2-years and 0.773 (95% CI 0.736-0.810) at 5-years, and there was good-to-excellent discrimination across disease aetiologies. Calibration plots revealed underestimation of risk at 2-years and overestimation of risk at 5-years, especially in high-risk patients. There was, however, underestimation of risk in patients with ADPKD for all KFRE calculations. The predictive accuracy was similar between the 4- and 8-variable KFREs. Finally, compared to eGFR-based thresholds, the KFRE was the optimal tool to guide further care based on decision curve analyses.
The 4- and 8-variable KFREs demonstrate adequate discrimination and calibration for predicting ESRD in an advanced CKD population and, importantly, can provide better clinical utility than using an eGFR-based strategy to inform decision-making.
肾衰竭风险方程（KFRE）预测了慢性肾脏病（CKD）3a-5 期患者的 2 年和 5 年终末期肾脏病（ESRD）风险。其在晚期 CKD 中的预测性能和特定疾病病因学方面需要进一步探讨。本研究通过评估鉴别力、校准和临床实用性，在英国的晚期 CKD 人群中验证了 4 变量和 8 变量 KFRE。
纳入 2011 年至 2018 年期间在索尔福德皇家国民保健制度基金会信托公司的高级肾脏护理服务（AKCS）诊所就诊的索尔福德肾脏研究中的患者。在首次 AKCS 就诊时计算 4 变量和 8 变量 KFRE，并将 2 年内和 5 年内发生 ESRD（透析或预防性移植）的观察结果作为主要结局。使用接收者操作特征曲线下面积（AUC）和校准图分别评估整个队列和特定疾病病因学（糖尿病肾病、高血压肾病、肾小球肾炎、常染色体显性多囊肾病（ADPKD）和其他疾病）中的鉴别力和校准。使用决策曲线分析评估临床实用性，比较使用 KFRE 与估计肾小球滤过率（eGFR）截断值<20 ml/min/1.73m 和<15 ml/min/1.73m 来指导进一步治疗的净收益。
共有 743 例患者纳入 2 年分析，613 例患者纳入 5 年分析。整个队列的鉴别力良好：4 变量 KFRE 对 2 年内 ESRD 的预测 AUC 为 0.796（95%置信区间[CI] 0.762-0.831），5 年内 AUC 为 0.773（95%CI 0.736-0.810），且在不同病因学中具有良好至卓越的鉴别力。校准图显示，2 年内风险低估，5 年内风险高估，尤其是高危患者。然而，对于所有 KFRE 计算，ADPKD 患者的风险都被低估了。4 变量和 8 变量 KFRE 的预测准确性相似。最后，与基于 eGFR 的阈值相比，基于 KFRE 的决策分析是指导进一步治疗的最佳工具。
4 变量和 8 变量 KFRE 对晚期 CKD 人群中 ESRD 的预测具有足够的鉴别力和校准能力，重要的是，与基于 eGFR 的策略相比，它可以提供更好的临床实用性，从而为决策提供信息。
