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 provides an estimate of glomerular filtration rate based on serum creatinine levels adjusted for age, gender, and race factors.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is crucial for diagnosing chronic kidney disease, determining disease stage, and guiding medication dosing in renal impaired patients.

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 main difference between MDRD and CKD-EPI equations?
A: The MDRD equation is more accurate in patients with established kidney disease, while CKD-EPI performs better at higher GFR levels and is less likely to misclassify individuals.

Q2: What are the limitations of the MDRD equation?
A: The equation may be less accurate in elderly patients, those with normal or near-normal kidney function, and in populations with different body compositions.

Q3: When was the MDRD equation developed?
A: The MDRD equation was developed in 1999 and has been widely used for estimating GFR in clinical practice.

Q4: Are there different versions of the MDRD equation?
A: Yes, there are several versions including the 4-variable and 6-variable MDRD equations. This calculator uses the 4-variable version.

Q5: Should MDRD be used for drug dosing?
A: While MDRD provides a good estimate of kidney function, for precise drug dosing in critical situations, measured GFR may be preferred.