1. What is the CKD-EPI Creatinine Equation?

The CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation estimates glomerular filtration rate (GFR) from serum creatinine, age, and sex. This specific formula provides an accurate assessment of kidney function using updated coefficients.

2. How Does the Calculator Work?

The calculator uses the CKD-EPI 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 different coefficients for different demographic groups using updated parameters.

3. Importance of eGFR Calculation

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

5. Frequently Asked Questions (FAQ)

Q1: Why use this specific CKD-EPI formula?
A: This version uses updated coefficients (142, -1.200, 0.9938, 1.012) that may provide improved accuracy in certain populations.

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 or unusual muscle mass.

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 high-risk populations.