Estimate GFR using the 4-variable MDRD equation — widely reported by Indian labs.
When to use: MDRD eGFR is still reported by many Indian pathology laboratories alongside creatinine results. Use it to confirm CKD stage and assess severity, particularly when GFR is below 60 mL/min/1.73 m² where MDRD performs adequately. Prefer CKD-EPI 2021 for clinical decisions and for patients with GFR near-normal range, as MDRD systematically underestimates GFR above 60.
MDRD (Modification of Diet in Renal Disease) study: original derivation cohort had CKD — hence it is less accurate at normal GFR.
Four-variable MDRD: age, sex, serum creatinine, [race — removed in modern use]; does NOT require weight.
MDRD systematically underestimates eGFR in healthy individuals — many labs now report "≥60" rather than an exact number above 60.
CKD-EPI has largely replaced MDRD in clinical guidelines (KDIGO, ACC/AHA, ADA 2024) — know both for exams.
Serum creatinine alone is a poor marker of GFR — a small rise (e.g., 0.9 to 1.8 mg/dL) can represent a 50% loss of kidney function.
References
Levey AS et al. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation (MDRD) · Ann Intern Med (1999)
Stevens LA et al. Assessing kidney function — measured and estimated glomerular filtration rate · N Engl J Med (2006)
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