Calibration and random variation of the serum creatinine assay as critical elements of using equations to estimate glomerular filtration rate
Calibration and random variation of the serum creatinine assay as critical elements of using equations to estimate glomerular filtration rate
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DOI：
10.1053/ajkd.2002.32765
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发表时间：
2002-05-01
影响因子：
13.2
通讯作者：
Levey, AS
中科院分区：
文献类型：
--
作者：
Coresh, J;Astor, BC;Levey, AS
在临床实践和研究中，经常使用血清肌酐水平、年龄、性别和其他患者特征的方程来估计肾小球滤过率（GFR）。然而，这些方程对血清肌酐测定校准的关键依赖性经常被忽视，估计GFR的可重复性很少被讨论。我们从2000年11月第二次测定血清肌酐水平的212名肾脏疾病饮食改变（MDRD）研究参与者和342名第三次全国健康与营养调查（NHANES 111）参与者的冷冻样本中解决了这些问题。在1919名NHANES III参与者中评估了血清肌酐水平的变化，这些参与者在两次访问中间隔17天测量血清肌酐。线性回归用于比较估计。血清肌酐的校准在不同的实验室和时间有很大的不同。数据表明，在NHANES III研究中，相同样品的血清肌酐测定值比MDRD研究高0.23 mg/dL。来自美国病理学家学会的数据表明，不同实验室之间这种程度的差异并不罕见。相反，平均间隔2周的血清肌酐测定具有更好的准确性（估计GFR差异百分比的标准差为15%；21%内估计的90%）。校正误差对估计严重下降的GFR (
Equations using serum creatinine level, age, sex, and other patient characteristics often are used to estimate glomerular filtration rate (GFR) in both clinical practice and research studies. However, the critical dependence of these equations on serum creatinine assay calibration often is overlooked, and the reproducibility of estimated GFR is rarely discussed. We address these issues in frozen samples from 212 Modification of Diet in Renal Disease (MDRD) study participants and 342 Third National Health and Nutrition Examination Survey (NHANES 111) participants assayed for serum creatinine level a second time during November 2000. Variation in serum creatinine level was assessed in 1,919 NHANES III participants who had serum creatinine measured on two visits a median of 17 days apart. Linear regression was used to compare estimates. Calibration of serum creatinine varied substantially across laboratories and time. Data indicate that serum creatinine assays on the same samples were 0.23 mg/dL higher in the NHANES III than MDRD study. Data from the College of American Pathologists suggest that a difference of this magnitude across laboratories is not unusual. Conversely, serum creatinine assays an average of 2 weeks apart have better precision (SD of percentage of difference in estimated GFR, 15%; 90% of estimates within 21%). Errors in calibration make little difference in estimating severely decreased GFR (