1. What is the MDRD 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 from the Modification of Diet in Renal Disease study and is widely used for assessing kidney function.

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 evaluating kidney function, detecting 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, while MDRD may underestimate GFR in healthy individuals.

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

Q3: When should creatinine be measured?
A: For most accurate results, measure creatinine in a fasting state and avoid testing after heavy meat consumption or exercise.

Q4: Are there limitations to the MDRD equation?
A: It's less accurate in extremes of age/weight, pregnant women, and those with rapidly changing kidney function.

Q5: Is this equation suitable for all populations?
A: The equation was developed primarily for patients with chronic kidney disease and may be less accurate in healthy populations.