Performance of estimating equations compared with GFR based on inulin single-injection method in children with a solitary functioning kidney
| Equation | Mean Bias (ml/min per 1.73 m2)a | 95% Limits of Agreement (ml/min per 1.73 m2)b | Proportion of eGFR within ±30% of GFR-Inulin (%) | Proportion of eGFR within ±10% of GFR-Inulin (%) |
|---|---|---|---|---|
| eGFR-Schwartz | 0.4 | −35.2 to 36.1 | 90 | 33 |
| Ccreat | −29.9 | −96.5 to 36.7 | 55 | 14 |
| eGFR-Zappitelli1 | −1.2 | −32.9 to 30.5 | 87 | 46 |
| eGFR-Zappitelli2 | −2.8 | −32.3 to 26.7 | 90 | 44 |
| eGFR-CKiD1 | 2.3 | −27.1 to 31.8 | 94 | 46 |
| eGFR-CKID2 | −0.9 | −25.1 to 23.3 | 95 | 55 |
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.
↵a Bias = GFR-inulin–estimated equation.
↵b 95% limits of agreement = mean bias ±1.96×SD.