Validation of estimated glomerular filtration rate equations for Japanese children
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The gold standard for evaluation of kidney function is renal inulin clearance (Cin). However, the methodology for Cin is complicated and difficult, especially for younger children and/or patients with bladder dysfunction. Therefore, we developed a simple and easier method for obtaining the estimated glomerular filtration rate (eGFR) using equations and values for several biomarkers, i.e., serum creatinine (Cr), serum cystatin C (cystC), serum beta-2 microglobulin (β2MG), and creatinine clearance (Ccr). The purpose of the present study was to validate these equations with a new data set.
To validate each equation, we used data of 140 patients with CKD with clinical need for Cin, using the measured GFR (mGFR). We compared the results for each eGFR equation with the mGFR using mean error (ME), root mean square error (RMSE), P30, and Bland–Altman analysis.
The ME of Cr, cystC, β2MG, and Ccr based on eGFR was 15.8 ± 13.0, 17.2 ± 16.5, 15.4 ± 14.3, and 10.6 ± 13.0 ml/min/1.73 m2, respectively. The RMSE was 29.5, 23.8, 20.9, and 16.7, respectively. The P30 was 79.4, 71.1, 69.5, and 92.9%, respectively. The Bland–Altman bias analysis showed values of 4.0 ± 18.6, 5.3 ± 16.8, 12.7 ± 17.0, and 2.5 ± 17.2 ml/min/1.73 m2, respectively, for these parameters.
The bias of each eGFR equation was not large. Therefore, each eGFR equation could be used.
KeywordsValidation Equation of estimated glomerular filtration rate Children Japanese
Compliance with ethical standards
Conflict of interest
The authors have declared that no conflict of interest exists.
Human and animal rights
All procedures involving human participants were in accordance with ethical standards of the institution at which the studies were conducted (Approval Number in Japanese Red Cross Nagoya Daini Hospital 1065), and with standards of the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Written informed consent was not obtained, because of use of retrospective data for clinical use. This information is noted on the website (opt-out).
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