Performance in adolescents of the two Japanese serum creatinine based estimated glomerular filtration rate equations, for adults and paediatric patients: A study of the Japan Renal Biopsy Registry and Japan Kidney Disease Registry from 2007 to 2013
In Japan, different serum creatinine‐based equations are used to calculate estimated glomerular filtration rate (eGFR) in children and adults. In children aged 2–18 years, reference serum creatinine concentrations (ref Cr) are calculated based on height (Ht).1 In boys, ref Cr is calculated using the formula, −1.259Ht5 + 7.815Ht4–18.57Ht3 + 21.39Ht2–11.71Ht + 2.628, whereas, in girls, ref Cr is calculated as −4.536Ht5 + 27.16Ht4–63.47Ht3 + 72.43Ht2–40.06Ht + 8.778. Following the determination of ref Cr, eGFR (mL/min per 1.73 m2) is calculated in children as 110.2 × (ref Cr / s‐Cr) +2.93. In adults aged ≥18 years, eGFR is calculated using the formula: eGFR (mL/min per 1.73 m2) = 194 x serum Cr‐1.094 × age‐0.287 × 0.739 (if female).2
Both of these equations are considered applicable to 18‐year‐old subjects. This study assessed the relative accuracy of the two equations in assessing eGFR in patients aged about 18 years with chronic kidney disease (CKD).