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, particularly in patients with chronic kidney disease.

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 — African American 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 diagnosing and staging chronic kidney disease, monitoring disease progression, and adjusting medication dosages for renal clearance.

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: When should I use MDRD vs CKD-EPI?
A: CKD-EPI is generally preferred as it's more accurate at higher GFR levels, but MDRD may still be used in certain clinical settings or research studies.

Q2: What are the limitations of the MDRD equation?
A: It may underestimate GFR in healthy individuals and is less accurate in extremes of age, body size, or muscle mass.

Q3: Why does race affect GFR estimation?
A: African Americans tend to have higher muscle mass and creatinine production, requiring adjustment for accurate GFR estimation.

Q4: Can this be used for acute kidney injury?
A: No, the equation was developed for stable chronic kidney disease and may not be accurate in acute settings.

Q5: How often should GFR be monitored?
A: Frequency depends on baseline kidney function and clinical context - consult with a healthcare provider.