Glomerular Filtration Rate
MDRD Equation (Modification of Diet in Renal Disease)
Result
Estimated Glomerular Filtration Rate (eGFR)
Classification:
KDIGO Stage:
Diagnosis of CKD requires persistent abnormality for more than 3 months
Note: For eGFR > 60 mL/min/1.73 m², MDRD tends to underestimate renal function. Consider confirming with the CKD-EPI 2021 equation, recommended by current guidelines for this range.
Note (KDIGO 2012): eGFR ≥ 60 mL/min/1.73 m² alone does not establish a diagnosis of CKD. At least one additional marker of kidney damage is required (albuminuria, glomerular hematuria, tubular disorder, histological finding, imaging finding, or renal transplant), persisting for more than 3 months.
Renal Function Classification — KDIGO 2012
| eGFR (mL/min/1.73 m²) | Classification | Stage |
|---|---|---|
| ≥ 90 | Normal or elevated | G1 |
| 60 – 89 | Mildly decreased | G2 |
| 45 – 59 | Mildly to moderately decreased | G3a |
| 30 – 44 | Moderately to severely decreased | G3b |
| 15 – 29 | Severely decreased | G4 |
| < 15 | Kidney failure | G5 |
About the MDRD Equation
Re-expressed equation (IDMS — current standard)
eGFR = 175 × (Creatinine)^(−1.154) × (Age)^(−0.203) × (0.742 if female) × (1.212 if Black)
The coefficient 175 is used for creatinine measured by IDMS-traceable methods (Levey et al., 2006), which is the standard of modern laboratories. The original 1999 publication used the coefficient 186, applicable only to non-IDMS methods.
Clinical Application
The MDRD equation was developed and validated in patients with established chronic kidney disease. It provides estimated GFR already normalized to standard body surface area of 1.73 m², without requiring patient weight.
Limitations
MDRD tends to underestimate eGFR in individuals with normal or near-normal renal function (eGFR > 60 mL/min/1.73 m²). For this range, current guidelines recommend the CKD-EPI 2021 equation, which performs better and does not include a race variable.
Note on the racial coefficient
The multiplier for Black race (1.212) is part of the original validated MDRD equation. In 2021, the NKF-ASN Task Force recommended adopting the CKD-EPI 2021 equation — which removes the racial factor — as the preferred equation for eGFR estimation.
Note: eGFR alone does not establish a diagnosis of chronic kidney disease. Diagnosis requires persistent abnormality for more than 3 months, associated with other markers of kidney damage where applicable. This tool does not replace nephrological assessment.
References
- 1. Levey AS, et al. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Ann Intern Med. 1999;130(6):461–470. PubMed ↗
- 2. Levey AS, et al. Using standardized serum creatinine values in the modification of diet in renal disease study equation for estimating glomerular filtration rate. Ann Intern Med. 2006;145(4):247–254. PubMed ↗
- 3. KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int Suppl. 2013;3(1):1–150. PubMed ↗
- 4. Inker LA, Eneanya ND, Coresh J, et al. New Creatinine- and Cystatin C–Based Equations to Estimate GFR without Race. N Engl J Med. 2021;385(19):1737–1749. PubMed ↗