1. What is the MDRD Formula?

The MDRD (Modification of Diet in Renal Disease) formula 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 relationship between creatinine and GFR, with demographic adjustments for gender and race.

3. Importance of GFR Calculation

Details: GFR estimation is essential for diagnosing and staging chronic kidney disease, monitoring disease progression, and adjusting medication dosages for renal clearance.

4. Using the Calculator

Tips: Enter serum creatinine in mg/dL, age in years, select gender and race. Ensure all values are valid (creatinine > 0, age between 1-120 years).

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between MDRD and CKD-EPI?
A: MDRD is more accurate in patients with established CKD, while CKD-EPI performs better at higher GFR levels and is less likely to over-diagnose CKD in healthy individuals.

Q2: What are the limitations of the MDRD formula?
A: Less accurate in elderly patients, those with normal or near-normal kidney function, amputees, and individuals with extreme body composition.

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

Q4: Is MDRD suitable for all populations?
A: The equation was validated primarily in Caucasian and African American populations with CKD. Accuracy may vary in other ethnic groups.

Q5: Can MDRD be used for drug dosing?
A: While commonly used, for precise drug dosing in critical situations, measured GFR may be preferred, especially in patients with unstable renal function.