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 is widely used in clinical practice for assessing kidney function and staging 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 relationship between creatinine and GFR, with demographic adjustments for gender and race.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is essential for diagnosing kidney disease, monitoring disease progression, and adjusting medication dosages based on renal function.

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 is 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 and is less likely to misclassify early kidney disease.

Q2: What are the limitations of the MDRD equation?
A: Less accurate in elderly patients, extremes of body size, pregnant women, and populations with normal or near-normal kidney function.

Q3: When should I use MDRD vs CKD-EPI?
A: MDRD is often used in established CKD patients, while CKD-EPI is preferred for screening and early detection of kidney disease.

Q4: Are there age restrictions for using MDRD?
A: The equation is validated for adults 18 years and older. Different equations should be used for pediatric patients.

Q5: How often should eGFR be monitored?
A: Frequency depends on clinical context - annually for screening, more frequently for known CKD patients or those at high risk.