1. What is GFR?

GFR (Glomerular Filtration Rate) is the best overall index of kidney function. It represents the flow rate of filtered fluid through the kidney. The foundation endorsed formula provides a more accurate assessment of kidney function.

2. How Does the Calculator Work?

The calculator uses the foundation endorsed formula:

Where:

• \( Scr \) — Serum creatinine (mg/dL)
• Age — Age in years
• Gender — Biological sex
• Race — Ethnic background

Explanation: The equation accounts for non-linear relationship between creatinine and GFR, with different coefficients for different demographic groups.

3. Importance of GFR Calculation

Details: Accurate GFR estimation is crucial for diagnosing chronic kidney disease, determining disease stage, and guiding 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).

5. Frequently Asked Questions (FAQ)

Q1: Why use this formula?
A: This foundation endorsed formula is more accurate at higher GFR levels (>60 mL/min/1.73m²) and less likely to misclassify people with mildly reduced kidney function.

Q2: What are normal GFR values?
A: Normal is generally ≥90 mL/min/1.73m², though values decline with age. Below 60 for 3+ months indicates CKD.

Q3: When should creatinine be measured?
A: Morning fasting sample is ideal, but random samples are acceptable. Avoid testing after meat-heavy meals or vigorous exercise.

Q4: Are there limitations to this equation?
A: Less accurate in extremes of age/weight, amputees, pregnant women, and those with rapidly changing kidney function.

Q5: Should this be used for drug dosing?
A: For precise drug dosing, measured GFR (e.g., via iohexol clearance) may be needed in certain populations.