Table 4.

CKD stage based on Kidney Disease Outcomes Quality Initiative guidelines for GFR-inulin and estimating equations in children with a solitary functioning kidney

EquationCKD Stage
Stage 1 (>90 ml/min per 1.73 m2)Stage 2 (≥ 60 to < 90 ml/min per 1.73 m2)Stage 3–5 (< 60 ml/min per 1.73 m2)Misclassification of CKD Stage (Compared with GFR-Inulin)
GFR-inulin33 (43)32 (42)12 (16)
eGFR-Schwartz26 (34)38 (49)13 (17)33 (43)
Ccreat51 (66)16 (21)10 (13)34 (44)
eGFR-Zappitelli134 (44)34 (44)9 (12)17 (22)
eGFR-Zappitelli232 (42)35 (46)10 (13)21 (27)
eGFR-CKiD121 (27)47 (61)9 (12)26 (34)
eGFR-CKiD232 (42)34 (44)11 (14)19 (25)
  • Data are presented as number of patients (%). Misclassification is defined as the proportion of patients with an unequal CKD stage between GFR-inulin and the estimating equation. GFR-inulin, GFR based on inulin single-injection method; eGFR-Schwartz, estimated GFR based on serum creatinine; Ccreat, urinary creatinine clearance; eGFR-Zappitelli1, estimated GFR based on serum cystatin C; eGFR-Zappitelli2, estimated GFR based on serum cystatin C and creatinine; eGFR-CKiD [Chronic Kidney Disease in Children] 1, estimated GFR based on serum cystatin C; eGFR-CKiD2, estimated GFR based on serum cystatin C, creatinine, and BUN.