Serum – reported with all serum creatinine results including renal function test profiles.
Adults: Calculated result using the CKD-EPI 2009 formula
1 to 18 years: Calculated result using Revised Schwartz Formula (if recent height available on MyCare) as of 25/09/23
A variety of methods have been used. All are based on serum creatinine estimations.
Although the Cockcroft-Gault formula is widely used, it was developed to permit estimation of CrCl, not of GFR.
The current recommended equation for 18 years and over is the CKD-EPI formula.
It is important to be aware of the limitations of these equations (more info on eGFR from the UK CKD eGuide):
Most UK labs now report eGFR when returning creatinine values. When available, these values should be more accurate than calculations performed by you, as they should incorporate lab-specific correction factors. If not, here are some resources:
The UK Renal Association Website – www.renal.org/eGFR
Online calculator from nephron.com offers a CKD-EPI equation, and has a useful menu of alternatives including US units and also Cockroft-Gault. Take care to set units for creatinine correctly to umol/L (micromol/litre).
We do not use ethnicity adjustment within our CKD-EPI eGFR equation. This is in line with national guidance that these adjustments may not be valid or accurate. See: UKKA for more information.
mL/min/1.73m^2
see NICE CKD guideline recommendations for interpretation: NICE NG203
Estimation of glomerular filtration rate.
Values above 90 mL/min/1.73 m^2 reported as >90 mL/min/1.73^2
Calculated for patients 18 years or above using CKD-EPI 2009
Calculated for patients 1 to 18 years if height recorded in MyCare within 3 months of sample using revised Schwartz formula
Local
Specimen Labelling Procedure
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