Calculation of GFR Equation

Ckd-Epi 2021 Creatinine Equation

CKD-EPI 2021 Equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

Estimated GFR (eGFR):

Unit Converter ▲

Unit Converter ▼

From:	To:

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

The CKD-EPI 2021 (Chronic Kidney Disease Epidemiology Collaboration 2021) equation estimates glomerular filtration rate (GFR) from serum creatinine, age, and sex. This updated version provides improved accuracy in GFR estimation compared to previous equations.

2. How Does the Calculator Work?

The calculator uses the CKD-EPI 2021 equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

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 for improved accuracy across different demographic groups.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is crucial for diagnosing chronic kidney disease, determining disease stage, monitoring disease progression, and guiding appropriate medication dosing for patients with renal impairment.

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). Use fasting serum creatinine values for most accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What's new in the CKD-EPI 2021 equation?
A: The 2021 version features updated coefficients (142, -1.200, 0.9938) and gender factors (1.012) based on more diverse population data for improved accuracy.

Q2: How does CKD-EPI 2021 compare to the original CKD-EPI?
A: The 2021 equation provides better performance across diverse populations and improved calibration, especially in non-Black individuals.

Q3: What are the clinical implications of using this equation?
A: May lead to different CKD staging in some patients compared to older equations, potentially affecting treatment decisions and monitoring frequency.

Q4: Is race still used in the CKD-EPI 2021 equation?
A: No, the CKD-EPI 2021 equation eliminates race as a variable, focusing only on creatinine, age, and sex for more equitable GFR estimation.

Q5: When should this equation be used clinically?
A: This equation is recommended for adults with stable kidney function. For special populations or rapidly changing renal function, clinical judgment and additional testing may be needed.