Stopping using Freestyle Libre

[Magarr]

Mod edit - Split from an old thread here: https://forum.diabetes.org.uk/boards/threads/freestyle-libre-huge-reading-errors.62059/page-2

Folks, thanks for the input.

I was aware, anecdotally, of people having a 24hour bed in time. However this it's not mentioned anywhere in the manual (from what I can see), and there's a big difference in an error of 1,2 or even 3 mmol/L and one of 8. Even after 15 hours the error was huge (libre 9, finger 5). Then after 21 hours Libre 14, finger 8.

I did phone. The advisor did say that this could happen, but acknowledged that it was not explicit anywhere.

So someone sticks in a sensor, waits 1-24 hours then dose adjusts... Doesn't give a lot of confidence in the product.

I have graphed the data. The error (for this sensor anyway) is much less at much lower readings. This indicates it gives visibility of low blood sugars. However at mid to higher readings it is miles out. Looks fairly linear too.

So should we be doing finger sticks to check the sensor after application? Again no mention of this...

Cheers

Hi just joined today and read this. I've just stopped using libre 2. I ran simultaneous Libre and finger pricking tests for 6 weeks. The libre was, on a stage, 3.51 points lower than finger pricking rests - that's a unit of insulin. I started doing this as I couldn't figure out why hba1c was so much higher than indicative libre estimate. For example, libre would tell me 6.7 at dinner but blood would would 10.1. using libre, I was taking insulin equal to carbs. Using blood, I'd have taken an extra unit of insulin. It's bad enough this happens but I've now been diagnosed with cheiroarthropathy (diabetic hand syndrome) which can be caused by high blood glucose! My BG could have been 3.51 higher at every injection for the 2.5 years I've been using libre. Gutted and have recently asked Abbott to treat my email detailing this, as a complaint. There's not enough info on checking BG regularly to ensure libre is accurate.

 

[Magarr]

From what I can see they only recommend/instruct finger pricks if your blood glucose is changing rapidly - as indicated by the arrow when making the measure - due to the lag in interstitial vs. blood glucose measure. The actual slow moving data is represented by abbott as being accurate. If it is not then the use of the thing is becomes very limited - finger tests needed over the first 1-2 days to check accuracy then a test needed before adjusting any dose - shades of the glucowatch and certainly not what abbott portray it as.

For those people using it, do you have confidence in the numbers to an accuracy of 1-2 mmol?

Cheers

No. Average difference for me is 3.51 with libre being lower than blood. I've not been taking enough insulin as I've accepted libre results. I've been diagnosed with cheiroarthropathy (diabetic hand syndrome) which can be caused by high blood glucose! I'm livid and have raised a complaint with Abbott about the inaccuracies and their information which doesn't contain enough info about the potential consequences.

 

[everydayupsanddowns]

I’ve split your posts into a new thread @Magarr as many of the posters involved no longer visit the forum.

Sorry to hear you’ve been seeing some unsatisfactory results from your Libre. Were these Libre1 or Libre2?

As you probably know continuous monitors and capillary blood meters measure very different things, and there is a ‘lag’ between the two sets of data, so differences are frequently seen where BG is rising or falling. Some people do seem to have more challenges with getting certain continuous sensors to give them data they feel they can rely on, so I can completely understand your disappointment.

Sorry to hear about the cheiroarthropathy - do you know if it’s possible for that to clear up? Or will it be a case of managing it, and trying to keep your BGs in range as much as possible to keep it from progressing?

 

[Inka]

That’s shocking @Magarr I don’t use the Libre because it’s very hard to get in my area, but when I first asked and was told the numerous hoops I’d have to jump through, my consultant comforted me by saying it probably wouldn’t be suitable for me as I like to keep my control pretty tight. I asked if it was accurate and she said not for the way in which I control my blood sugar. This was the first Libre but that made me feel very worried. If I was going to have to check with a finger prick there seemed little reason to have it.

I hope your cheiroarthropathy improves. Good on you for complaining.

 

[nonethewiser]

I asked if it was accurate and she said not for the way in which I control my blood sugar. This was the first Libre but that made me feel very worried. If I was going to have to check with a finger prick there seemed little reason to have it.

Mind 2 version has alarms so ideal for those who want tight control, you can set alarms to alert you when bg goes up or down your chosen targets.

 

[Inka]

Mind 2 version has alarms so ideal for those who want tight control, you can set alarms to alert you when bg goes up or down your chosen targets.

Yes, the alarms sound good on Libre 2, especially for nighttime. But my concern would be that I’d be doubting it’s accuracy so would still feel I had to fingerprick to check.

I think @helli has her own set up which gives her better accuracy. If I could get (was that a pig flying by 🙄 ) I think I’d look into that. My control isn’t perfect but I do try to keep it tight most of the time and I’d be horrified to think things had been ok and then to find out my 7.1 had actually been a 10.1 or whatever.

 

[helli]

@Inka, even with my set up, I still check a high or low alert with a finger prick. Despite calibration, I still find Libre less accurate when high or low.
But I am happy at “normal levels” to bolus from my ”pimped” Libre levels.

That said, each sensor is different and some drift so to say all sensors read 3.51 (or even an average of 3.51) is quite a generalisation.
Furthermore, even with my ability to calibrate, I check my readings with a finger prick at least twice a day and would highly recommend any sensor is checked daily to spot any that are out by more than 1 mol/l.

 

[PattiEvans]

I find Libre 1 extraordinarily accurate. I always fingerprick to bolus as my pump handset won't allow manual input. it's frequently within 0.5 mmol

 

[rebrascora]

I have been using the Libre 1 for just over a year now and so far most sensors have been pretty accurate and I have felt very confident to bolus from them but I do check each sensor with 2-3 finger pricks in the first day or 2 and sometimes when hypo or hyper if it doesn't tie in with a general trend or the way I feel and the odd double check when my levels are stable during the life of the sensor. I would not trust it without checking it occasionally and I am sure the training advises double checking when hypo or hyper. However I often go 3 or 4 days without doing any finger prick BG checks.
For me it's predicted HbA1c is usually a few points lower than my actual HbA1c but only 3-5 mmols which I think is perfectly reasonable. I do resent the fact that it shows I have a lot more hypos than I actually do, but my consultant has not expressed any concern about the number of hypos it has logged although I do aim to keep the TIR % at 3 or less below 3.9 as much as possible. I tend to average just over 1 hypo a day according to Libre and that has been pretty standard over the course of a year. I rarely double check hypos now but may have just 1 JB rather than a conventional 3 to treat a "proper" hypo.

I do find it quite surprising that you have taken all Libre readings at face value over that period of time without doing some checks and becoming aware there was a discrepancy. I do think that the system seems to be "happier" in some people's bodies (or perhaps their bodies are more accepting of it) than others and I think the factory "calibration" suits some people better than others. I tend to just factor in that it will read about 0.5-1mmol lower than a finger prick would, when I calculate boluses and corrections as that is what my finger prick checks show as being a pretty consistent discrepancy. I had 1 sensor which seemed to be consistently 2mmols lower a few months ago and whilst I found that a bit frustrating, I just adjusted my doses and thinking to deal with that. It showed I had quite a few hypos that I didn't treat but I can justify that if my consultant wanted to query it.
At the end of the day, it is a tool and you have to work out the best way to use it for you.

 

[Diastard]

I think Libre type CGM that put a wire into the interstitial can vary in performance based on your personal physical characteristics and the lottery of where it is sited when applied. However, if you know the general difference between your current sensor readings and your normal fingerprick reading, then it is a trivial matter to do a correction in your head. It is also very clear, from the graph type traces, which direction your BG is headed and when it has stopped climbing and heading down again. This can be very useful for a T2 who wants to learn about their body's response to various things.
I don't use them currently, because they are too expensive. I took the trial 2 weeks and Abbott sent me two.

 

[mikeyB]

It isn’t a wire that is inserted with the Libre, it’s a plastic filament carried in by the needle which then withdraws. It’s probably made from nylon or similar. It’s Bio inert, anyway. If you site it where Abbott tell you to, that eliminates one variable. Their algorithm accounts for that site to improve its accuracy, particularly in Libre 2.

 

[Diastard]

Within the area that Abbott suggest the sensor is sited there is quite a scope for differences in physiology. It's no more specific than "the back of the upper arm".

 

[nonethewiser]

Yes, the alarms sound good on Libre 2, especially for nighttime. But my concern would be that I’d be doubting it’s accuracy so would still feel I had to fingerprick to check.

No harm in double checking when in doubt, overall find sensors mostly accurate, more so with 2 version.