Riku Hamda1, Yoshimitsu Gotoh2, Osamu Uemura3, Kenji Ishikura4, Tomoyuki Sakai5, Yuko Hamasaki6, Yoshinori Araki7, Masataka Honda1. 1. Department of Nephrology, Tokyo Metropolitan Children's Medical Center, 2-8-29 Musasidai, Futyu-shi, Tokyo, Tokyo, 183-8561, Japan. 2. Department of Pediatric Nephrology, Japanese Red Cross Nagoya Daini Hospital, 2-9 Myoken-cho Showa-ku, Nagoya, Aichi, 466-8650, Japan. ygotoh@nagoya2.jrc.or.jp. 3. Department of Clinical Medicine, Japanese Red Cross Toyota College of Nursing, 12-33 Nanamagari, Hakusan-cho, Toyota, Aichi, 471-8565, Japan. 4. Department of Nephrology and Rheumatology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo, 157-8535, Japan. 5. Department of Pediatrics, Shiga University of Medical Science, Seta, Ootsu, Shiga, 520-2192, Japan. 6. Department of Pediatric Nephrology, Toho University Faculty of Medicine, 6-11-1 Oomori Nishi Seta, Ootsu, Shiga, 143-8541, Japan. 7. Department of Pediatrics, Hokkaido Medical Center, 5-7-1-1 Yamanote 5jyo Nishi-ku, Sapporo, Hokkaido, 063-0005, Japan.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: The bias of each eGFR equation was not large. Therefore, each eGFR equation could be used.
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: The bias of each eGFR equation was not large. Therefore, each eGFR equation could be used.
Entities:
Keywords:
Children; Equation of estimated glomerular filtration rate; Japanese; Validation
Authors: George J Schwartz; Alvaro Muñoz; Michael F Schneider; Robert H Mak; Frederick Kaskel; Bradley A Warady; Susan L Furth Journal: J Am Soc Nephrol Date: 2009-01-21 Impact factor: 10.121