1. What is the NKF GFR Equation?

The National Kidney Foundation (NKF) GFR equation estimates glomerular filtration rate from serum creatinine, age, sex, and race. It was developed to provide a standardized method for assessing kidney function and staging chronic kidney disease.

2. How Does the Calculator Work?

The calculator uses the NKF GFR equation:

Where:

• \( Scr \) — Serum creatinine (mg/dL)
• \( age \) — Age in years
• 0.742 — Female multiplier
• 1.212 — African American race multiplier

Explanation: The equation accounts for the inverse relationship between creatinine and GFR, with adjustments for age, gender, and race.

3. Importance of GFR Calculation

Details: GFR estimation is essential for detecting kidney disease, monitoring progression, and making treatment decisions. It helps classify chronic kidney disease into stages.

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's the difference between NKF and CKD-EPI equations?
A: The NKF equation is older but still widely used. CKD-EPI is generally more accurate, especially at higher GFR levels.

Q2: What are normal GFR values?
A: Normal GFR is typically ≥90 mL/min/1.73m². Values below 60 for 3+ months suggest chronic kidney disease.

Q3: When should this equation not be used?
A: Not recommended for children, pregnant women, or those with extremely high/low muscle mass.

Q4: How often should GFR be calculated?
A: Frequency depends on clinical context - annually for at-risk patients, more often for those with known kidney disease.

Q5: Why is race included in the calculation?
A: Studies show African Americans typically have higher muscle mass and creatinine production, requiring adjustment.