1. What is the MDRD GFR Equation?

The MDRD (Modification of Diet in Renal Disease) equation estimates glomerular filtration rate (GFR) from serum creatinine, age, sex, and race. It was developed to provide a more accurate assessment of kidney function than the Cockcroft-Gault equation.

2. How Does the Calculator Work?

The calculator uses the MDRD equation:

Where:

• \( Scr \) — Serum creatinine (mg/dL)
• \( Age \) — Age in years
• 0.742 — Female multiplier
• 1.212 — Black race multiplier

Explanation: The equation accounts for the inverse relationship between creatinine and GFR, with adjustments for age, gender, and race.

3. Importance of GFR Calculation

Details: GFR estimation is essential for assessing kidney function, diagnosing chronic kidney disease, and determining appropriate medication doses.

4. Using the Calculator

Tips: Enter serum creatinine in mg/dL, age in years, select gender and race. All values must be valid (creatinine > 0, age between 1-120).

5. Frequently Asked Questions (FAQ)

Q1: Why use MDRD equation?
A: The MDRD equation is widely validated and more accurate than Cockcroft-Gault, especially in patients with chronic kidney disease.

Q2: What are normal GFR values?
A: Normal GFR is typically ≥90 mL/min/1.73m². Values below 60 for 3+ months suggest chronic kidney disease.

Q3: When is MDRD less accurate?
A: MDRD may be less accurate in healthy individuals, extremes of age, amputees, and those with unstable creatinine levels.

Q4: How does MDRD compare to CKD-EPI?
A: CKD-EPI is generally more accurate at higher GFR levels (>60), while MDRD may underestimate GFR in this range.

Q5: Should MDRD be used for drug dosing?
A: For precise drug dosing, especially with narrow therapeutic windows, measured GFR may be preferable.