Estimates adult eGFR (mL/min/1.73 m²) using the 4-variable MDRD Study equation, derived in 1628 adults with chronic kidney disease with measured GFR by 125I-iothalamate clearance.
The original 6-variable equation included urea and albumin. A simplified 4-variable version using serum creatinine, age, sex and African ancestry was re-expressed for standardized creatinine, giving the 175× MDRD formula implemented here.
Accuracy is best for eGFR <60 mL/min/1.73 m². The equation systematically underestimates measured GFR at higher levels, so many laboratories only report MDRD eGFR values below 60.
KDIGO 2012 CKD guidance stages disease using G1-G5 eGFR categories together with albuminuria and chronicity, usually ≥3 months. G3a-G5 generally indicate CKD if persistent, whereas G1-G2 require additional markers of kidney damage.
The original MDRD equation includes a race coefficient. Current NKF/ASN and NIDDK guidance favours race-free CKD-EPI equations for routine eGFR reporting, so use MDRD mainly when interpreting historical results or publications based on this equation.
Not validated in children, pregnancy, acute kidney injury or other non-steady-state renal function.

MDRD GFR Equation