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 as an improvement over the Cockcroft-Gault equation and is widely used in clinical practice.

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 assessing kidney function, diagnosing chronic kidney disease, and determining appropriate medication dosages.

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: What's the difference between MDRD and CKD-EPI equations?
A: CKD-EPI is generally more accurate, especially at higher GFR levels (>60 mL/min/1.73m²), while MDRD may underestimate GFR in healthier individuals.

Q2: When was the MDRD equation developed?
A: The MDRD equation was developed in 1999 and validated in patients with chronic kidney disease.

Q3: Are there limitations to the MDRD equation?
A: Yes, it's less accurate in healthy individuals, the elderly, and those with extreme body sizes or unstable creatinine levels.

Q4: Why is race included in the equation?
A: Studies showed that African Americans tend to have higher muscle mass and creatinine production, requiring adjustment for accurate GFR estimation.

Q5: Should I use MDRD or CKD-EPI?
A: CKD-EPI is now preferred in most clinical settings, but MDRD may still be used in certain situations or for comparison with older studies.