The MDRD GFR Equation calculator helps estimate how well your kidneys are filtering blood, expressed as the estimated glomerular filtration rate (eGFR). This measurement reflects kidney function and helps determine stages of chronic kidney disease (CKD). To use this calculator, you'll need to know four things: gender, age, serum creatinine level, and race.

Serum creatinine levels, integral to the calculation, must first be standardized. If your creatinine level is provided in micromoles per liter (µmol/L), convert it to milligrams per deciliter (mg/dL) by dividing by 88.4. This ensures that all calculations are consistent.

With this information, the MDRD formula estimates the eGFR: 

- eGFR = 175 × (creatinine^(-1.154)) × (age^(-0.203))

Specific adjustments are made to this calculation for certain demographics:
- Multiply the result by 0.742 if you are female. This accounts for differences in muscle mass, as women generally have less muscle mass compared to men.
- Multiply by 1.212 if you are Black, as studies have shown distinct genetic factors that influence kidney function.

After computing the eGFR, the value is rounded to the nearest whole number. This final figure places you in one of the CKD stages, each reflecting a range of kidney function:

- Stage 1: eGFR of 90 or more, indicating normal kidney function with some kidney damage.
- Stage 2: eGFR between 60 to 89, suggesting mild decrease in kidney function.
- Stage 3a: eGFR between 45 to 59, indicating a mild to moderate decrease.
- Stage 3b: eGFR between 30 to 44, showing a moderate to severe decrease.
- Stage 4: eGFR between 15 to 29, indicating severely reduced function.
- Stage 5: eGFR less than 15, which is considered kidney failure.

This estimation assists healthcare providers in understanding kidney health over different stages, guiding treatment decisions and health management.

The MDRD GFR Equation estimates the Glomerular Filtration Rate (eGFR) using serum creatinine, age, gender, and race, adjusted for body surface area. It is widely used for early detection of Chronic Kidney Disease (CKD) and provides an accurate assessment of kidney function without requiring urine collection, making it practical for routine clinical use.

MDRD GFR Equation

A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group.