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's widely used for assessing kidney function 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 multiplier

Explanation: The equation accounts for the inverse relationship between creatinine and GFR, with adjustments for demographic factors.

3. Importance of GFR Calculation

Details: GFR estimation is essential for evaluating kidney function, detecting kidney disease progression, 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: What's the difference between MDRD and CKD-EPI?
A: CKD-EPI is generally more accurate at higher GFR levels (>60 mL/min/1.73m²), while MDRD is better for advanced CKD.

Q2: What are normal GFR values?
A: Normal GFR varies by age but is typically ≥90 mL/min/1.73m² for young adults, decreasing with age.

Q3: When should creatinine be measured?
A: Ideally in the morning after fasting, but random measurements are acceptable in most cases.

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: Should this be used for drug dosing?
A: For critical medications, measured GFR may be needed for precise dosing in certain populations.