Quick link: to the GFR Calculator (CKD-EPI formula)
Simple language fact sheet for patients: estimated Glomerular Filtration Rate (eGFR) formula
Note: The eGFR MDRD measurement of GFR has been superceded by the CKD-EPI formula
Early detection and treatment for CKD can reduce the progression and cardiovascular risk associated with CKD by up to 50% and may also improve quality of life. Routine testing for individuals at increased risk of CKD is important and easily carried out in Primary Care.
People at increased risk of CKD should have a Kidney Health Check.
Early detection of CKD - using the Kidney Health Check
*1 year for individuals with diabetes or hypertension
For further information see our treatment guideline book CKD Management in General Practice>
TESTS FOR KIDNEY HEALTH
Blood Tests - eGFR
The glomerular filtration rate (GFR) measures how well the kidneys filter waste products from the blood and is the best assessment of kidney function.
GFR is difficult to measure and so an eGFR is used in clinical practice. eGFR stands for ‘estimated Glomerular Filtration Rate’ and is estimated from serum creatinine using prediction equations that include age, gender and creatinine level.
In Australia the recommended equation is the CKD-EPI formula.
eGFR is recommended to be automatically reported by all Australian pathology laboratories (using the CKD-EPI equation) with every request for serum creatinine in individuals aged 18 or over. It can also be calculated by using our online GFR (CKD-EPI formula) Calculator>
eGFR is reported in millilitres per minute and is shown as mL/min/1.73m2.
If your eGFR is less than 90, the actual value will be shown.
eGFR results of 90 or greater may be shown as the actual value or they may be reported as eGFR > 90 mL/min/1.73m2 depending on the preference of the pathology laboratory.
A normal GFR in healthy adults is greater than or equal to 90 mL/min/1.73m2 and declines with age.
Further investigation of eGFR is usually only needed when the eGFR result is less than or equal to ≤ 60 mL/min/1.73m2.
eGFR results above 60 should not be considered abnormal unless accompanied by signs of kidney damage such as protein or blood in the urine, an abnormal ultrasound or biopsy.
An eGFR needs to be consistently below 60 for a period of 3 months before CKD is diagnosed.
Excessive amounts of proteins in the urine are a key marker of kidney damage and of increased renal and cardiovascular disease risk. The preferred urine test in all people at increased risk of CKD is an urine Albumin: Creatinine Ratio (ACR). This test gives an accurate picture of the amount of protein (albumin) that is present in the urine. The appearance of albumin in the urine (called albuminuria) may be the first sign of an otherwise silent kidney condition.
Your doctor may ask you to collect a urine sample first thing in the morning, right after you get up (called a first void sample). If this is not practical, your doctor can still do the test on a sample of urine collected at any time during the day (called a spot random sample).
If this test result is positive, then your doctor will repeat the test two times within the next three months to see if you have persistent albuminuria.
Urine dipsticks for protein are no longer recommended as the sensitivity and specificity is not optimal.
The Staging of CKD
Staging of CKD is now determined by the combined results of kidney function (eGFR) and the level of albuminuria. Further info on eGFR and ACR tests and CKD staging can be found in our publication for health professionals
- Chronic Kidney Disease Management in General Practice.
Chronic Kidney Disease Management in General Practice
This is the 2nd edition of our popular CKD guideline booklet for General Practice which supercedes the previous version and contains important new information.
- New CKD staging system and colour-coded action plans
- New recommendations albuminuria
- New eGFR recommendations
- New blood pressure targets
Book is available for PDF download - or in hard-copy
You may also order the booklet by using this Order Form>
Note: Third edition (updated) available 1st quarter 2015
Email your contact details to KCAT@kidney.org.au - overseas order are not available.
This booklet is formally endorsed by RACGP, the ANZSN and Kidney Health Australia
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Quick links onsite - publications of interest
CKD in Australia I Kidney Check Australia Taskforce (KCAT) I GFR Calculator (CKD-EPI formula)
QKidney® Risk Assessment I CVD Risk Calculator I Kidney Health Resources> I Organ Donation
Updated 20 November 2014 - Disclaimer: This information is intended as a general introduction to this topic and is not meant to substitute for your doctor's or health professional's advice. All care is taken to ensure the information is relevant and applicable to each Australian state. It should be noted Kidney Health Australia recognises each person's experience is individual and variations do occur in treatment and management due to personal circumstances. Should you require further info always consult your doctor or health professional.