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 to provide a more accurate assessment of kidney function than serum creatinine alone.

2. How Does the Calculator Work?

The calculator uses the MDRD equation:

Where:

• \( Cr \) — Serum creatinine (mg/dL)
• \( Age \) — Age in years
• 0.742 — Female multiplier
• 1.21 — 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, 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?
A: MDRD is more accurate at lower GFR levels (<60 mL/min/1.73m²), while CKD-EPI performs better at higher GFR levels.

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

Q3: When should creatinine be measured?
A: Ideally in the morning after fasting, but random samples are acceptable. Avoid testing after high-protein meals.

Q4: Are there limitations to this equation?
A: Less accurate in extremes of age/weight, pregnant women, and those with rapidly changing kidney function.

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