Department of Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
Nephrol Dial Transplant. 2013 Jul;28(7):1773-9. doi: 10.1093/ndt/gft063. Epub 2013 May 3.
Patients with chronic kidney disease (CKD) are at risk for progression to kidney failure. Using data of Canadian CKD patients, Tangri et al. recently developed models to predict the progression of CKD stages 3-5 to kidney failure within 5 years. We validated this kidney failure risk equation (KFRE) in European CKD patients.
We selected non-transplanted patients with CKD stages 3-5 who participated in the MASTERPLAN study, a randomized controlled trial in patients with CKD. Kidney failure was defined as the initiation of chronic dialysis or kidney transplantation within 5 years. Patients who died before kidney failure were censored. Patients followed for <5 years, who did not develop kidney failure and did not die, were excluded. The 5-year kidney failure risk was predicted using three different models developed by Tangri et al. and compared with the actual kidney failure rate in MASTERPLAN. Model performance was evaluated using the area under the receiver operating characteristic curve (ROC-AUC), the net reclassification index (NRI) and by comparing the observed and predicted rates of kidney failure.
A total of 595 patients were included; 114 developed kidney failure. (Overall observed kidney failure risk in our cohort was 5% lower than in the Canadian validation cohort.) Discrimination of the eight-variable model [including age, sex, estimated glomerular filtration rate (eGFR), albuminuria, calcium, phosphate, bicarbonate, albumin] was similar to that of the four-variable model (including age, sex, eGFR, albuminuria) and the three-variable model (including age, sex, eGFR); ROC-AUCs were 0.89 [95% confidence interval (CI) 0.86-0.92], 0.88 (95% CI 0.85-0.91) and 0.88 (95% CI 0.85-0.92), respectively. Using the NRI, the eight-variable model slightly outperformed the four-variable model (NRI 6.5%) and the three-variable model (NRI 12.4%). The mean differences between the observed and predicted kidney failure risk were -4.0, -7.1 and -7.4% for the eight-, four-, and three-variable model, respectively.
The KFRE accurately predicted the progression to kidney failure in European CKD patients. Discrimination of the three models was similar. Calibration of the eight-variable model was slightly better than that of the simpler models. We question whether this outweighs its added complexity.
患有慢性肾脏病（CKD）的患者有进展为肾衰竭的风险。Tangri 等人最近利用加拿大 CKD 患者的数据开发了预测 CKD 3-5 期进展为 5 年内肾衰竭的模型。我们在欧洲 CKD 患者中验证了这个肾衰竭风险方程（KFRE）。
我们选择了参加 MASTERPLAN 研究的非移植 CKD 3-5 期患者，这是一项 CKD 患者的随机对照试验。肾衰竭的定义为 5 年内开始慢性透析或肾移植。在肾衰竭发生前死亡的患者被删失。随访时间<5 年、未发生肾衰竭且未死亡的患者被排除。使用 Tangri 等人开发的三种不同模型预测 5 年肾衰竭风险，并与 MASTERPLAN 中的实际肾衰竭发生率进行比较。使用受试者工作特征曲线下面积（ROC-AUC）、净重新分类指数（NRI）和比较观察到的和预测的肾衰竭率来评估模型性能。
共纳入 595 例患者，其中 114 例发生肾衰竭。（我们队列中的总体观察到的肾衰竭风险比加拿大验证队列低 5%。）包括年龄、性别、估计肾小球滤过率（eGFR）、白蛋白尿、钙、磷、碳酸氢盐和白蛋白在内的八变量模型的区分度与四变量模型（包括年龄、性别、eGFR 和白蛋白尿）和三变量模型（包括年龄、性别、eGFR）相似；ROC-AUC 分别为 0.89（95%CI 0.86-0.92）、0.88（95%CI 0.85-0.91）和 0.88（95%CI 0.85-0.92）。使用 NRI，八变量模型略优于四变量模型（NRI 6.5%）和三变量模型（NRI 12.4%）。八变量、四变量和三变量模型的观察到的和预测的肾衰竭风险之间的平均差异分别为-4.0%、-7.1%和-7.4%。
KFRE 准确预测了欧洲 CKD 患者向肾衰竭的进展。三个模型的区分度相似。八变量模型的校准稍好于简单模型。我们怀疑这是否超过了其复杂性。
