Table 3.

Mayo Clinic eGFR Clinic Equation Performancea

Mean Absolute BiasPrecision (SD)Mean % BiasPrecision (SD)Median Absolute BiasPrecision (IQR)Accuracy % Within 30%
Full cohort (n = 94)
    eGFR (Mayo Clinic)−5.412.2−7.022.7−4.916.680
    eGFR (CHEO)1.814.76.428.11.019.979
    eGFR (CHEO corrected)−4.914.3−6.025.4−4.719.378
CysC <1.41 (n = 47)
    eGFR (Mayo Clinic)−4.114.5−2.124.7−3.723.582
    eGFR (CHEO)5.317.712.030.34.428.776
    eGFR (CHEO corrected)−2.617.5−0.427.5−3.828.280
CysC ≥1.41 (n = 47)
    eGFR (Mayo Clinic)−6.79.3−11.919.6−5.211.474
    eGFR (CHEO)−1.79.80.924.8−0.8013.674
    eGFR (CHEO corrected)−7.19.9−12.421.7−5.513.272
  • a Bias, percent bias, and precision expressed in ml/min per 1.73 m2. Bias was defined as the absolute difference between the eGFR and the mGFR (eGFR − mGFR), and as the percentage difference ([eGFR − mGFR]/ mGFR × 100). A negative bias indicates that the GFR is underestimated by the prediction equation. Precision was described by both the interquartile range of the median bias and the standard deviation (SD) of the mean bias. Accuracy was defined as the percentage of eGFR estimates lying within 30% of the mGFR. eGFR, estimated GFR; IQR, interquartile range; CysC, cystatin C; CHEO, Children's Hospital of Eastern Ontario; mGFR, measured GFR.