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 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 — Black race multiplier

Explanation: The equation uses a power function to model the inverse relationship between serum creatinine and GFR, with adjustments for demographic factors.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is essential for diagnosing chronic kidney disease, staging disease severity, and guiding treatment decisions including medication dosing.

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 years).

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between MDRD and CKD-EPI equations?
A: CKD-EPI is generally more accurate at higher GFR levels (>60 mL/min/1.73m²) and is less likely to misclassify individuals with normal or mildly reduced kidney function.

Q2: What are the limitations of the MDRD equation?
A: MDRD may underestimate GFR in healthy individuals and is less accurate in elderly patients, pregnant women, and those with extreme body sizes.

Q3: When is MDRD preferred over CKD-EPI?
A: MDRD may still be used in some clinical settings and for comparison with historical data, though CKD-EPI is now recommended for most applications.

Q4: How often should eGFR be monitored?
A: Frequency depends on clinical context - from annually in stable CKD to more frequently in acute kidney injury or rapidly progressing disease.

Q5: Can this calculator be used for children?
A: No, the MDRD equation is validated for adults only. Pediatric GFR estimation requires different equations.