1. What is the UK Kidney eGFR Calculator?

The UK Kidney eGFR Calculator uses the CKD-EPI 2021 equation to estimate glomerular filtration rate (GFR) from serum creatinine, age, and sex. This updated equation provides improved accuracy for assessing kidney function in the UK population.

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 optimized coefficients for the UK population based on 2021 research.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is crucial for diagnosing chronic kidney disease, determining disease stage, and guiding medication dosing in clinical practice.

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 the CKD-EPI 2021 equation?
A: The 2021 version provides improved accuracy and calibration for the UK population compared to previous equations.

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

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: Is this calculator suitable for all ethnicities?
A: This version is optimized for the UK population. For other ethnic groups, consult specific validated equations.