Table 2.

Comparison of performance of MDRD Study equation by level of eGFRa

eGFRNDifference% DifferenceP30 (CI)
Median (CI)IQRMedian (CI)IQR
Overall55042.7 (2.4 to 3.1)16.45.8 (5.1 to 6.4)27.683 (83 to 84)
>120325−9.0 (−12.3 to −5.9)31.2−7.1 (−10.1 to −4.6)26.682 (80 to 84)
90 to 11994111.1 (9.7 to 12.6)25.69.9 (8.6 to 11)20.889 (88 to 90)
60 to 8913649.5 (8.3 to 10.7)25.411.7 (10.2 to 12.7)28.082 (81 to 83)
30 to 5917821.7 (1.1 to 2.3)13.03.5 (2.4 to 4.9)27.484 (83 to 85)
16 to 297930.0 (−0.4 to 0.5)6.70.0 (−1.8 to 2.4)31.481 (80 to 82)
<152990.8 (0.3 to 1.4)5.06.3 (2.5 to 11.1)34.572 (69 to 75)
  • a Units of GFR are in ml/min per 1.73 m2. Difference is calculated as mGFR − eGFR. Percentage difference is calculated as (mGFR − eGFR)/mGFR. Median values measure bias, and IQR measure precision. mGFR ranges in the rows correspond to GFR cutoffs for CKD stages: Stage 1, GFR >90; stage 2, GFR 60 to 89; stage 3, GFR 30 to 59; stage 4, GFR 15 to 29; stage 5, GFR <15. CI, confidence interval.