Egfr Calculator

eGFR Calculator (CKD-EPI Creatinine 2009)

function calculateEGFR() { var creatinine = parseFloat(document.getElementById('creatinine').value); var age = parseInt(document.getElementById('age').value); var sex = document.querySelector('input[name="sex"]:checked').value; var race = document.querySelector('input[name="race"]:checked').value; var resultDiv = document.getElementById('egfrResult'); if (isNaN(creatinine) || creatinine <= 0) { resultDiv.innerHTML = 'Please enter a valid Serum Creatinine value (e.g., 0.1 – 10.0 mg/dL).'; return; } if (isNaN(age) || age 120) { resultDiv.innerHTML = 'Please enter a valid Age (18-120 years).'; return; } var kappa; // κ var alpha; // α var sexFactor = 1; var raceFactor = 1; if (sex === 'female') { kappa = 0.7; alpha = -0.329; sexFactor = 1.018; } else { // male kappa = 0.9; alpha = -0.411; sexFactor = 1; // Explicitly set for clarity, though default is 1 } if (race === 'black') { raceFactor = 1.159; } else { // nonblack raceFactor = 1; // Explicitly set for clarity, though default is 1 } var min_scr_kappa = Math.min(creatinine / kappa, 1); var max_scr_kappa = Math.max(creatinine / kappa, 1); var egfr = 141 * Math.pow(min_scr_kappa, alpha) * Math.pow(max_scr_kappa, -1.209) * Math.pow(0.993, age) * sexFactor * raceFactor; resultDiv.innerHTML = 'Your estimated GFR (eGFR) is: ' + egfr.toFixed(2) + ' mL/min/1.73m2'; var interpretation = "; if (egfr >= 90) { interpretation = 'Stage 1: Normal or High GFR (with other evidence of kidney damage)'; } else if (egfr >= 60 && egfr = 45 && egfr = 30 && egfr = 15 && egfr < 30) { interpretation = 'Stage 4: Severely Decreased GFR'; } else { // egfr < 15 interpretation = 'Stage 5: Kidney Failure'; } resultDiv.innerHTML += 'Interpretation (CKD Stage): ' + interpretation + ''; resultDiv.innerHTML += 'This calculation is based on the CKD-EPI Creatinine Equation (2009). Always consult a healthcare professional for diagnosis and treatment.'; } .calculator-container { background-color: #f9f9f9; border: 1px solid #ddd; padding: 20px; border-radius: 8px; max-width: 600px; margin: 20px auto; font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; } .calculator-container h2 { color: #333; text-align: center; margin-bottom: 20px; } .calc-input-group { margin-bottom: 15px; display: flex; flex-wrap: wrap; align-items: center; } .calc-input-group label { flex: 1; min-width: 150px; margin-right: 10px; color: #555; font-weight: bold; } .calc-input-group input[type="number"] { flex: 2; padding: 10px; border: 1px solid #ccc; border-radius: 4px; min-width: 120px; box-sizing: border-box; } .calc-input-group input[type="radio"] { margin-left: 10px; margin-right: 5px; } .calculate-button { display: block; width: 100%; padding: 12px 20px; background-color: #007bff; color: white; border: none; border-radius: 4px; font-size: 18px; cursor: pointer; margin-top: 20px; transition: background-color 0.3s ease; } .calculate-button:hover { background-color: #0056b3; } .calc-result { margin-top: 25px; padding: 15px; border: 1px solid #e0e0e0; border-radius: 4px; background-color: #e9f7ef; color: #333; font-size: 1.1em; } .calc-result p { margin: 5px 0; } .calc-result strong { color: #0056b3; } .calc-result .error { color: #dc3545; font-weight: bold; } .calc-result .disclaimer { font-size: 0.9em; color: #666; margin-top: 15px; }

Understanding Your eGFR: A Key Indicator of Kidney Health

The Estimated Glomerular Filtration Rate (eGFR) is a crucial measure used by healthcare professionals to assess kidney function. It indicates how well your kidneys are filtering waste products from your blood. A healthy GFR means your kidneys are working efficiently, while a decreased GFR can signal kidney damage or chronic kidney disease (CKD).

What is GFR?

GFR stands for Glomerular Filtration Rate. The glomeruli are tiny filters in your kidneys that remove waste, toxins, and excess fluid from your blood. The GFR measures the rate at which these filters are working. Since directly measuring GFR is complex and invasive, eGFR is calculated using a formula that estimates this rate based on readily available blood test results.

Why is eGFR Important?

  • Early Detection of Kidney Disease: A low eGFR can be an early sign of kidney problems, even before symptoms appear.
  • Staging CKD: eGFR is used to classify the stage of chronic kidney disease, which helps guide treatment and management.
  • Monitoring Kidney Health: Regular eGFR checks help track the progression of kidney disease and the effectiveness of treatments.
  • Medication Dosing: Many medications are cleared by the kidneys, so eGFR helps doctors adjust drug dosages to prevent accumulation and side effects.

How is eGFR Calculated? The CKD-EPI Creatinine Equation (2009)

Our calculator uses the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) Creatinine Equation from 2009. This formula is widely recommended because it is more accurate than older equations, especially for individuals with normal or mildly reduced kidney function. It takes into account several factors:

  • Serum Creatinine (mg/dL): Creatinine is a waste product from muscle metabolism. Healthy kidneys filter it out of the blood. Higher creatinine levels generally indicate lower kidney function.
  • Age (years): Kidney function naturally declines with age.
  • Sex (Male/Female): Biological sex influences muscle mass and, consequently, creatinine levels.
  • Race (Black/Non-Black): The original CKD-EPI 2009 equation included a race factor. This was based on observations that, on average, Black individuals tend to have higher muscle mass and thus higher creatinine levels for the same GFR. However, it's important to note that the use of race in eGFR calculations is a subject of ongoing debate and is being phased out or adjusted in newer guidelines due to concerns about perpetuating racial bias and its limited biological basis. Many institutions are now moving towards race-neutral equations. Our calculator includes this option for historical accuracy with the 2009 formula, but we encourage users to discuss this with their healthcare provider.

Interpreting Your eGFR Results (CKD Stages)

eGFR values are typically reported in milliliters per minute per 1.73 square meters (mL/min/1.73m2), which adjusts for average body surface area. Here's a general guide to interpreting your eGFR:

  • eGFR ≥ 90: Normal or High GFR. If there are other signs of kidney damage (e.g., protein in urine), this could be Stage 1 CKD.
  • eGFR 60-89: Mildly Decreased GFR. If there are other signs of kidney damage, this could be Stage 2 CKD.
  • eGFR 45-59: Mild-to-Moderately Decreased GFR (Stage 3a CKD).
  • eGFR 30-44: Moderately-to-Severely Decreased GFR (Stage 3b CKD).
  • eGFR 15-29: Severely Decreased GFR (Stage 4 CKD).
  • eGFR < 15: Kidney Failure (Stage 5 CKD). At this stage, dialysis or kidney transplant may be necessary.

Important Considerations

  • Acute Kidney Injury: eGFR is best for assessing chronic kidney function. It may not accurately reflect sudden changes in kidney function (acute kidney injury).
  • Muscle Mass: Factors affecting muscle mass (e.g., amputation, malnutrition, extreme bodybuilding, certain diseases) can influence creatinine levels and thus eGFR accuracy.
  • Diet: A very high-protein diet or creatine supplements can temporarily increase creatinine levels.
  • Medications: Some medications can affect creatinine levels or kidney function.
  • Individual Variation: eGFR is an estimate. Your doctor will consider your overall health, medical history, and other tests to make a diagnosis.

Disclaimer: This eGFR calculator is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider for any health concerns or before making any decisions related to your health or treatment.

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