Table 3. Comparison of Performance of CKD-EPI and MDRD Study Equations in the Validation Dataset.
| Variable and Equation | All Patients | Patients with estimated GFR <60 ml/min/1.73 m2 | Patients with estimated GFR ≥60 ml/min/1.73 m2 |
|---|---|---|---|
| Median difference (95% CI), mL/min per 1.73 m2† | |||
| CKD-EPI | 2.5 (2.1 - 2.9) | 2.1 (1.7 - 2.4) | 3.5 (2.6 - 4.5) |
| MDRD Study | 5.5 (5.0 - 5.9) | 3.4 (2.9 - 4.0) | 10.6 (9.8 - 11.3) |
| Interquartile range for differences (95% CI) - mL/min per 1.73 m2‡ | |||
| CKD-EPI | 16.6 (15.9 - 17.3) | 11.3 (10.7 - 12.1) | 24.2 (22.8 - 25.3) |
| MDRD Study | 18.3 (17.4 - 19.3) | 12.9 (12.0 - 13.6) | 25.7 (24.4 - 27.1) |
| P30 (95% CI) - %§ | |||
| CKD-EPI | 84.1 (83.0 - 85.3) | 79.9 (78.1 - 81.7) | 88.3 (86.9 - 89.7) |
| MDRD Study | 80.6 (79.5 - 82.0) | 77.2 (75.5 - 79.0) | 84.7 (83.0 - 86.3) |
| Root mean square error (95% CI) | |||
| CKD-EPI | 0.250 (0.241 - 0.259) | 0.284 (0.270 - 0.298) | 0.213 (0.203 - 0.223) |
| MDRD Study | 0.274 (0.265 - 0.283) | 0.294 (0.280 - 0.308) | 0.248 (0.238 - 0.258) |
CKD-EPI = Chronic Kidney Disease Epidemiology Collaboration; GFR = glomerular filtration rate; MDRD = Modification of Diet in Renal Disease.
*
To convert GFR from mL/min per 1.73 m2 to mL/s per 1.73 m2, multiply by 0.0167.
†
Median difference refers to measured GFR minus estimated GFR.
‡
Interquartile range refers to the 25–75th percentile.
§
P30 refers to percentage of GFR estimates that are within 30% of measured GFR.