1. What is the CKD-EPI 2021 Creatinine Equation?

The CKD-EPI 2021 (Chronic Kidney Disease Epidemiology Collaboration) equation estimates glomerular filtration rate (GFR) from serum creatinine, age, and sex. This updated version provides improved accuracy in estimating kidney function without race adjustment.

2. How Does the Calculator Work?

The calculator uses the CKD-EPI 2021 equation:

Where:

• \( Scr \) — Serum creatinine (mg/dL)
• \( \kappa \) — 0.7 (female) or 0.9 (male)
• \( \alpha \) — -0.241 (female) or -0.302 (male)
• \( age \) — Age in years
• 1.012 — Female multiplier

Explanation: The equation accounts for non-linear relationship between creatinine and GFR, with updated coefficients based on recent research data.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is crucial for diagnosing chronic kidney disease, determining disease stage, and guiding medication dosing. The CKD-EPI 2021 equation provides race-free estimation of kidney function.

4. Using the Calculator

Tips: Enter serum creatinine in mg/dL, age in years, and select gender. All values must be valid (creatinine > 0, age between 1-120).

5. Frequently Asked Questions (FAQ)

Q1: Why use CKD-EPI 2021 instead of older versions?
A: CKD-EPI 2021 provides race-free estimation and improved accuracy based on contemporary patient data.

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

Q3: Why is there no race adjustment in this version?
A: The 2021 equation was developed without race variables to provide equitable kidney function assessment across all populations.

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.