I'm sure the old lags here know all about this and doubtless there is data about it kicking around, but it might help some newbies wondering about their variable eGFR results.
The eGFR is predominantly calculated from your blood creatinine, age, sex etc using an equation, but the equation has changed over the years, which gives slightly different results.
We have:
MDRD equation from 1999
CKD-EPI equation from 2009
CKD-EPI equation from 2021
The reason I bring it up is my NHS lab results of today - they are still using the 2009 calculation (per NICE guidelines as apparently Brits are different than Americans), which doesn't compare directly to recent private tests who were using the newer 2021 calculation.
My result today is an eGFR (2009) of 75, however if they had used the older MDRD equation it would have been 70, or if they had used the newer 2021 equation it would have been 80. Quite a spread.
There is also the CKD-EPI 2021 equation that uses Cystatin-C as well as creatinine, which some think of as more accurate or giving earlier detection - a previous result of mine using the 2021 equation and creatinine-only was eGFR 78, but when the cystatin-C number was added to the equation it came back as eGFR 55. Ouch.
Just for people to be aware when comparing results and trends over the last few years, you really need to try and ensure they are all using the same equation - you can plug your creatinine numbers into these links to check.
MY CKD JOURNEY..FROM EGFR OF 11 TO EGFR OF 84.. FROM AKI 5 TO CKD 2.. STRUGGLING WITH LOW SODIUM LEVELS.
eGFR vs GFR
Not braggin', but I must be doing something right
eGFR CKD STAGE
