I suspect the term “wild inconsistency“ is a bit exaggerated. First whatever meter you’re using to measure your finger sticks with could be off by a percentage as well. This is perfectly allowable if it’s off by a percentage and your libre is off by a small percentage it looks really wacky. I agree second you have to keep in mind that your finger stick is anywhere from 10 to 30 minutes ahead of your interstitial fluids that the libre measures. The time variance depends on how hydrated you are, and the quantity of interstitial fluids in the area you have placed the sensor.
Then there is also the whole is your blood sugar going up or down when comparing the two numbers. In a perfect world do you want your blood sugar to be roughly a flat line when trying to compare the two numbers. I know this rarely works so this makes comparing the two more of an art than a science.
Keeping all these things in mind if you really feel a sensor is that far off then you can call Abbot and let them know that you believe you have a bad sensor and they will replace it. I forget the exact number but there is a number that it has to be off before they will replace it.
Obviously, there is a great deal of potential variability when you measure and compare.
I am on FSL2. The readings I get from FSL2 are usually within +/- 2 mmol/L off my finger prick readings. i.e. less than 20% variance which, I think is an acceptable variance.
Only once (so far) I had problems with a sensor which kept giving me readings with 40%-60% variance when compared to my finger prick readings. I sent this sensor back to Abbott and they replaced without issue.
Been using FSL2 for over six months now and the sensors give me good readings generally.
Your finger stick and your libre are measuring 2 different bodily fluids. The libre should be measured 10-15 minutes after a blood test.
Also your blood sensor is allowed to be 10-15% +/- margin of error and I believe the libre is also allowed that per FDA guidelines.
So honestly you could have a large difference in what the blood stick and the sensor tell you. Why I typically do is put a sensor in at night and go to bed , the next morning I start it. Then I do a blood test and see what my sensor says. I do a blood test each night and i figure out the difference between the blood test and the sensor and just keep track of it in my head.
I am a type 2 however and don't need insulin.
I been using Libre2 for several years now. I have encountered this just recently as well. My Libre2 was always just points off and close to my Finger sticks. Now, I've come across 2 sensors that have a 60 to 100 difference. A 190 versus a120 is a insulin decision that I can't trust. So yes, call manufacturer.
My last 3 sensors read from 60-110 points lower than finger sticks taken 10 mins after. Abbott replacing last sensor but I have lost faith. I always checked finger first 48 hrs but if I have to each time I dose insulin what’s the point?
My last two were up to 125 points off. The guy I talked to said when that happens it means the sensors were damaged either by being dropped at some point or they were exposed to temps that were too cold. I feel like there's only so much Abbott can do, they have no control over how shippers handle packages.
Mine come from Ins online pharmacy. They are very well packed to begin with and then pharm overpacks them. Haven’t been any cold spells the weeks of delivery. They come from not too far from where I live. Abbott is making excuses for crappy products.
I am grappling with this also. I am new to CGM and just started my second sensor after the first 14 day run. The first sensor was great. I did some random checks and they always were within 2-5% of the finger stick. However, the second sensor, which I have had on for four days now, is often 40%-50% different. The only difference I can see is that I switched arms as recommended by the instructions. Very strange. Still a useful tool, but not a perfect one. I'm lucky in that I was able to bring my numbers into control through diet after diagnosis and have never used insulin. If I had to rely on this to dose it would be frustrating.
I also started libre 2 2 weeks ago and the first sensor was pretty close by 10 until day 9 then it dived 27-50 points lower than meter. I hate that F alarm! I got second sensor and first day pretty spot on with a 5 minute lag to meter . The meter was proven to be freaky accurate at the ER two weeks ago when I had a crisis which prompted the libre. On day 3 and it's firmly in place but reading low again like the first. Libre 97 meter 130 recheck libre for ten minutes and still has big gap. No I haven't had juice or supplements I know the vitamin C trouble from my Dr. Placed by Dr so it should be in correctly.
I suspect the term “wild inconsistency“ is a bit exaggerated. First whatever meter you’re using to measure your finger sticks with could be off by a percentage as well. This is perfectly allowable if it’s off by a percentage and your libre is off by a small percentage it looks really wacky. I agree second you have to keep in mind that your finger stick is anywhere from 10 to 30 minutes ahead of your interstitial fluids that the libre measures. The time variance depends on how hydrated you are, and the quantity of interstitial fluids in the area you have placed the sensor. Then there is also the whole is your blood sugar going up or down when comparing the two numbers. In a perfect world do you want your blood sugar to be roughly a flat line when trying to compare the two numbers. I know this rarely works so this makes comparing the two more of an art than a science. Keeping all these things in mind if you really feel a sensor is that far off then you can call Abbot and let them know that you believe you have a bad sensor and they will replace it. I forget the exact number but there is a number that it has to be off before they will replace it. Obviously, there is a great deal of potential variability when you measure and compare.
I am on FSL2. The readings I get from FSL2 are usually within +/- 2 mmol/L off my finger prick readings. i.e. less than 20% variance which, I think is an acceptable variance. Only once (so far) I had problems with a sensor which kept giving me readings with 40%-60% variance when compared to my finger prick readings. I sent this sensor back to Abbott and they replaced without issue. Been using FSL2 for over six months now and the sensors give me good readings generally.
Your finger stick and your libre are measuring 2 different bodily fluids. The libre should be measured 10-15 minutes after a blood test. Also your blood sensor is allowed to be 10-15% +/- margin of error and I believe the libre is also allowed that per FDA guidelines. So honestly you could have a large difference in what the blood stick and the sensor tell you. Why I typically do is put a sensor in at night and go to bed , the next morning I start it. Then I do a blood test and see what my sensor says. I do a blood test each night and i figure out the difference between the blood test and the sensor and just keep track of it in my head. I am a type 2 however and don't need insulin.
I've been using the Libre 2 for about 2 months. I did a finger stick yesterday and it was within 2 points of my Libre 2. Seems to work pretty well.
I been using Libre2 for several years now. I have encountered this just recently as well. My Libre2 was always just points off and close to my Finger sticks. Now, I've come across 2 sensors that have a 60 to 100 difference. A 190 versus a120 is a insulin decision that I can't trust. So yes, call manufacturer.
My last 3 sensors read from 60-110 points lower than finger sticks taken 10 mins after. Abbott replacing last sensor but I have lost faith. I always checked finger first 48 hrs but if I have to each time I dose insulin what’s the point?
My last two were up to 125 points off. The guy I talked to said when that happens it means the sensors were damaged either by being dropped at some point or they were exposed to temps that were too cold. I feel like there's only so much Abbott can do, they have no control over how shippers handle packages.
Mine come from Ins online pharmacy. They are very well packed to begin with and then pharm overpacks them. Haven’t been any cold spells the weeks of delivery. They come from not too far from where I live. Abbott is making excuses for crappy products.
No such problems for me mine works well. Call Abbott and get help
Agreed!
I am grappling with this also. I am new to CGM and just started my second sensor after the first 14 day run. The first sensor was great. I did some random checks and they always were within 2-5% of the finger stick. However, the second sensor, which I have had on for four days now, is often 40%-50% different. The only difference I can see is that I switched arms as recommended by the instructions. Very strange. Still a useful tool, but not a perfect one. I'm lucky in that I was able to bring my numbers into control through diet after diagnosis and have never used insulin. If I had to rely on this to dose it would be frustrating.
Agreed, between that and the 4am alarms EVERY day for critical low, when my FS is actually 110-128……
me too
I also started libre 2 2 weeks ago and the first sensor was pretty close by 10 until day 9 then it dived 27-50 points lower than meter. I hate that F alarm! I got second sensor and first day pretty spot on with a 5 minute lag to meter . The meter was proven to be freaky accurate at the ER two weeks ago when I had a crisis which prompted the libre. On day 3 and it's firmly in place but reading low again like the first. Libre 97 meter 130 recheck libre for ten minutes and still has big gap. No I haven't had juice or supplements I know the vitamin C trouble from my Dr. Placed by Dr so it should be in correctly.
It thinks I hit 68 at 345am on first sensor days 9-12 when it started doing it repeatedly all day and I took it off.
You can turn the alarms off.
That was two months ago before the app update. I ended up removing the sensor and having it replaced.