• Guest - w'd love to know what you think about the forum! Take the 2025 Survey »

Freestyle libre 2 calibration

Ack4

Newbie
Messages
2
Since march ,I have been having bid discrepancies between the freestyle libre 2 and my blood testing meter.I have found that the higher my scan the higher the discrepancies.Example scan says 9.2 mol but glucose meter says 16.1 mol. It seems as my level drops to say 5.6 scan,the blood glucose meter says 9.4. As it drops the discrepancies lessen. Scan says 3.9, glucose says 5.2. It seems that a newly fitted sensor ,when first tested is quite close,i.e.scan 5.4 meter says 5.9.mol. The next day the discrepancies seem to start.
Tried using two different phones with the app and two glucose meters. All with the same result. When I phone Abbott they say scanner must be faulty,then send me a new sensor.But nothing changes,I get the same discrepancies. Any thoughts on this from anyone please.
 
Since march ,I have been having bid discrepancies between the freestyle libre 2 and my blood testing meter.I have found that the higher my scan the higher the discrepancies.Example scan says 9.2 mol but glucose meter says 16.1 mol. It seems as my level drops to say 5.6 scan,the blood glucose meter says 9.4. As it drops the discrepancies lessen. Scan says 3.9, glucose says 5.2. It seems that a newly fitted sensor ,when first tested is quite close,i.e.scan 5.4 meter says 5.9.mol. The next day the discrepancies seem to start.
Tried using two different phones with the app and two glucose meters. All with the same result. When I phone Abbott they say scanner must be faulty,then send me a new sensor.But nothing changes,I get the same discrepancies. Any thoughts on this from anyone please.

Hello,
Welcome to the forum.

Let's see if we can help..
How close are you testing BGs to your scan?
What medication for your diabetes have you been prescribed?
 
Hmm. They calibrate them at the factory. A potential issue is that your body is not close enough to the factory standard. The libre 1 could be calibrated using xdrip+ but I don't know how this works with the libre 2. (I had to stop using the libre when I developed an allergy).

Alternatively, if this is an option, you could try out the dexcom g6, which does allow calibration.
 
Firstly bg meters are not 100% accurate

It think bg meters are within 15%. So yes the higher the reading the higher the chance of bigger difference

Libre Is within 20 or 25% it’s a while since I’ve read the spec so again if one’s wrong one the and the other wrong the other way there can be quite a difference


Also libre does not measure blood it’s the fluid under the skin so hydration helps.. but the fluid under the skin reacts slower than blood so only compare when your bg is stable

For me I never found the libre accurate
 
I also have never found the libre to be accurate, in fact, after my HbA1c went from 6% to 7.8% in 6 months, I did dual testing for a month, ie Libre and finger prick. The results showed anything between 2-5 mmols higher readings when I checked my bsl using meter. I stopped using the Libre sensors. Waste of money and completely inaccurate. I still use the Reader and have gone back to finger pricking which I prefer because at least the bsl results are accurate and my HbA1C has lowered. Hopefully one day the Libre technology etc will improve.
 
I also have never found the libre to be accurate, in fact, after my HbA1c went from 6% to 7.8% in 6 months, I did dual testing for a month, ie Libre and finger prick. The results showed anything between 2-5 mmols higher readings when I checked my bsl using meter. I stopped using the Libre sensors. Waste of money and completely inaccurate. I still use the Reader and have gone back to finger pricking which I prefer because at least the bsl results are accurate and my HbA1C has lowered. Hopefully one day the Libre technology etc will improve.

I wouldn’t say totally useless if you know it’s a bit out… good for trends and seeing what different foods do…
 
Range of discrepancy on mine - Libre shows between 3mmols to 0.5mmols lower than finger prick glucose test. I can accept that it understates, as it is based on the interstitial fluid glucose. However, it is the inconsistency that bothers me. Notwithstanding, to be able to see the graphical representation is good. Just that you cannot rely on the numbers....
 
Back
Top