Validation of the estimated glomerular filtration rate equation for Japanese children younger than 2 years

BACKGROUND: We have developed a simple and easy method of estimating the glomerular filtration rate (eGFR) of serum creatinine in Japanese children (eGFR(Uemura)). The eGFR equation is for children aged 2–18 years. Therefore Uemura et al. developed an equation for children younger than 2 years (eGFR(under 2)). The aim of the present study was to validate this new equation. METHODS: We collected the data of 13 patients from previous studies and compared the results of eGFR(under 2), eGFR(Uemura), and updated eGFR developed by Schwartz (eGFR(Schwartz)) with measured GFR using mean error (ME), root mean square error (RMSE), P(30) and Bland–Altman analysis. RESULTS: The ME of eGFR(under 2), eGFR(Uemura) and eGFR(Schwartz) were 2.3 ± 15.9, 7.7 ± 14.5, and 16.0 ± 18.2 ml/min/1.73m(2), respectively. The RMSEs were 15.5, 15.9, and 49.6, respectively. The P(30) values were 76.9%, 76.9%, and 53.8%, respectively. The graph of Bland–Altman bias analysis showed fan-shape. The eGFR(under 2) equation was the most accurate in the three equations. CONCLUSION: The eGFR(under 2) equation was useful for Japanese children younger than 2 years.