Why is Libre1 so inaccurate?

[corbanwolf]

Hey, I been using freestyle libre 1 for a year now and I haven't been doing glucose blood test, I was solely relying on libre so I wasn't double checking with glucose blood test. However, last 3 sensors were inaccurate as hell. This happened 5 min ago. I am just lying in bed browsing internet, and I feel like I have hypo, but my sensor shows 6.5mmol so I was like, hmmm maybe I am wrong. 10min later i check, it is 6.3mmol, so I suppose it is going down (slowly), but it haven't reached danger zone. But out of curiosity I checked from blood, and it showed 3.2mmol. I quickly treated my hypo. I know sensors are 15min behind, but it wouldn't go as low as 3.2mmol in 15min. My last 2 sensors were this inaccurate, and this is my third one which is inaccurate. I apply them in the right place, back of my upper arm and I think I haven't had problems before with inaccuracy. I called the support to get one replaced, they said they would send new one. Then second one was faulty but I didn't call them cuz they would think I am a scammer that tried to get free sensors. And now the third sensor I have on me, is also faulty. The other time I check, it shows rising glucose and currently is at 15,7mmol, and I check blood, and it says it's only 11.2mmol and it started falling. Before I haven't been testing with blood so I don't know if my old sensors were inaccurate. Just recently I started experience inaccuracies. I don't wanna call them every 2 weeks with faulty sensors. At first I was happy to have freestyle libre so I could manage my diabetes better, but now when I look at this. This is so dangerously inaccurate, I consider going back to blood test glucose.

And before, sometimes I wake up from blood glucose at 11mmol (from sensor), but then I check with strips, and it shows 7mmol. So. I am confused. It is 3rd sensor in a row to be so inaccurate. But I repeat, I haven't been testing with sensor and strips before, just recently decided to test both methods to check inconsistency.

Mod edit.

 

[searley]

Libre has alway had poor accuracy for me

Many get on ok with it

Still good for seeing trends with

And soon all libre1 will be replaced with the libre2 which is meant to be more accurate

 

[In Response]

I never fond Libre 1 to be accurate which is why I always used unofficial apps because they allow calibration against finger pricks.
Just assumed I was different to “Factory Man” - the guy they use for factory calibration.

I have found Libre 2 to be more accurate and am more comfortable bolusing against it.

 

[kaylz91]

Some people just don't get on with them, most of mine are well within the tolerated % difference but I have had a few replacements when they have become inaccurate from the 8th day, also I'd just report the others too, they ask for comparisons to BG so I doubt they think your scamming them, whats to benefit from getting a replacement for one that's not working correctly? Nobody in their right mind would continue with it so it's not like your gaining a free sensor for 2 weeks, I've called a fortnight between due to sensors falling off just last month and they had no issues with replacing both xx

 

[LittleGreyCat]

I have just switched over to Libre 2 and they seem much more accurate on me.
Libre 1 was often a whole unit out so I relied on it for trends, not an accurate reading.

 

[ert]

It works better when you can calibrate your readings using the Glimp or Xdrip apps. It's very good for trends. I always finger print to dose for insulin and check readings below 4 and above 7.

 

[searley]

It works better when you can calibrate your readings using the Glimp or Xdrip apps. It's very good for trends. I always finger print to dose for insulin and check readings below 4 and above 7.

When libre first launched the docs clearly stated not to be used for dosing decisions

Libre 1 and 2 do not confirm to icgm standards which means they are not approved to be connected to a pump for looping

Libre3 is claimed it will confirm as icgm and can be connected to pumps for treatment decisions.

I’ve used libre 1 with a Bluetooth bridge so basically like a cgm with xdrip or similar and yes it can be more accurate but is still more erratic than say the Dexcom

The Abbott website still states that if the way you feel doesn’t match the results you see you must confirm with a bg meter

However it’s still much better than nothing.. still very good to give an idea where your bg is.. still good to see the effects a meal has.. still good for seeing trends

 

[KK123]

I do like the libre but for those saying it's better for 'trends', my Diabetes team insist I use it to dose my insulin. When they gave it to me (for which I am very grateful because it helps me enormously), they said I would no longer need 'so many' blood test strips and reduced my prescription to one box per 6 weeks (roughly 1 per day). I do wonder if many others have been told the same. It would be a nuisance having to STILL do the same amount of finger prick tests as well and I haven't pushed it in case they say 'not accurate enough??, give it back'!!

 

[searley]

I do like the libre but for those saying it's better for 'trends', my Diabetes team insist I use it to dose my insulin. When they gave it to me (for which I am very grateful because it helps me enormously), they said I would no longer need 'so many' blood test strips and reduced my prescription to one box per 6 weeks (roughly 1 per day). I do wonder if many others have been told the same. It would be a nuisance having to STILL do the same amount of finger prick tests as well and I haven't pushed it in case they say 'not accurate enough??, give it back'!!

You don’t need to do as many.. but you do need to do enough to confirm the accuracy.. they are often not accurate enough to trust for treatment decisions which is why even the libre 2 can not get the icgm standard for use with a pump

As stated the Abbott website still has a field advisory notice to use a bg test if you suspect the libre may not be right

 

[corbanwolf]

I do like the libre but for those saying it's better for 'trends', my Diabetes team insist I use it to dose my insulin. When they gave it to me (for which I am very grateful because it helps me enormously), they said I would no longer need 'so many' blood test strips and reduced my prescription to one box per 6 weeks (roughly 1 per day). I do wonder if many others have been told the same. It would be a nuisance having to STILL do the same amount of finger prick tests as well and I haven't pushed it in case they say 'not accurate enough??, give it back'!!

After some time I noticed my allowance for repeat prescriptions for strips is limited. I will contact my GP to increase it. Because since my libre is not accurate. I will get back to daily bg test. And in my case is similar to yours. I am using accu check, and on average they want me to do 1 test a day. Which is way too low as of now.

 

[ert]

I do like the libre but for those saying it's better for 'trends', my Diabetes team insist I use it to dose my insulin. When they gave it to me (for which I am very grateful because it helps me enormously), they said I would no longer need 'so many' blood test strips and reduced my prescription to one box per 6 weeks (roughly 1 per day). I do wonder if many others have been told the same. It would be a nuisance having to STILL do the same amount of finger prick tests as well and I haven't pushed it in case they say 'not accurate enough??, give it back'!!

I was told when I got my Libre to never dose for insulin with it and to still do a minimum of 5 finger pricks a day. Waking, bedtime, and before breakfast, lunch and dinner. It was on my DAFNE course, run by the lead consultant and DN.

 

[In Response]

I was told when I got my Libre to never dose for insulin with it and to still do a minimum of 5 finger pricks a day. Waking, bedtime, and before breakfast, lunch and dinner. It was on my DAFNE course, run by the lead consultant and DN.

The guidance for Libre changed.
Initially, it was “never dose from Libre”.
Then they worked out how to justify the cost of Libre - reducing number of test strips used. After that, the guidance changed. Hence the qualification being anyone with 10 finger pricks per day should get Libre on prescription.

In my experience, Libre 2 accuracy is good enough for bolusing without the need for calibrations. But finger pricks are still needed for highs and lows.

 

[searley]

The guidance for Libre changed.
Initially, it was “never dose from Libre”.
Then they worked out how to justify the cost of Libre - reducing number of test strips used. After that, the guidance changed. Hence the qualification being anyone with 10 finger pricks per day should get Libre on prescription.

In my experience, Libre 2 accuracy is good enough for bolusing without the need for calibrations. But finger pricks are still needed for highs and lows.

Even the Dexcom, which is far superior in accuracy is not trouble free..

Looking forward to seeing the libre 3 and Dexcom g7 both will be icgm rated.. smaller etc. But the icgm rating should mean the are both accurate enough to bolus from

 

[KK123]

I was told when I got my Libre to never dose for insulin with it and to still do a minimum of 5 finger pricks a day. Waking, bedtime, and before breakfast, lunch and dinner. It was on my DAFNE course, run by the lead consultant and DN.

Hi ert, mine was a dafne course too, also run by a Consultant and a diabetes team. No wonder we all get confused. x

 

[KK123]

You don’t need to do as many.. but you do need to do enough to confirm the accuracy.. they are often not accurate enough to trust for treatment decisions which is why even the libre 2 can not get the icgm standard for use with a pump

As stated the Abbott website still has a field advisory notice to use a bg test if you suspect the libre may not be right

Hi there, I do use a finger prick test if the libre is showing very low (no probs with highs). The rest of the time though i check on the libre and dose accordingly as I was told.

 

[EllieM]

I was a libre 1 user for about 8 months before I developed an allergy to it, at which point the readings went seriously out of allignment, eg hypo readings when my bg was actually 6. Unfortunately the readings also randomly read too high as well. After several replacement sensors and even a reader from Abbott, I had to come to the conclusion that it was me and not them, and I went back to fingerpricks. But the first few iterations of dexcom required manual calibration from fingerpricks, so I always suspected that some people were just going to find that the libre wasn't working for them.

I've been a dexcom 6 user for about a year now, and find it much more accurate. Though I do an occasional check, particularly on a new sensor, the only time I really need my glucometer is if I have a bad hypo, when I need to know that I've had enough glucose and am not going to literally hit the floor. (Readings every 5 minutes are no good when your levels are falling off a cliff ).

But considering that libre 1 was just their first attempt (dexcom will be producing their seventh soon) I think Abbott are doing pretty well. You just have to accept that every technology has its limitations.

 

[Jaylee]

After some time I noticed my allowance for repeat prescriptions for strips is limited. I will contact my GP to increase it. Because since my libre is not accurate. I will get back to daily bg test. And in my case is similar to yours. I am using accu check, and on average they want me to do 1 test a day. Which is way too low as of now.

Hi,

You could try what I've been doing for years. Just order your strips on repeat in time for when you need them?
I order nearly every 2 weeks? Nobody bats an eyelid from the surgery.

I use the libre too. (But self fund.) I'm normally happy when the reading is within 0.6mmol to the meter.
(Remembering to take the reading 20minutes on the sensor prior to the meter test.)

My personal experience with the L2 in comparison to the L1. The L2 for me is more stable from the start to the end of it's life.
The L2 is also consistently close to the meter, not needing the tweaks & calibrations with MK1.

Staying suitably hydrated seems to help too..

 

[corbanwolf]

Hi,

You could try what I've been doing for years. Just order your strips on repeat in time for when you need them?
I order nearly every 2 weeks? Nobody bats an eyelid from the surgery.

I am using online repeat prescription system from my GP and an option to request test strips (test cassette) is greyed out. It says next available request is at date xxxx. " Last Issued: 11 Jan 2021 Cannot order medication until 14 Apr 21" I think I can order 100test every 3 months or so, which makes it around 100days for 100 test strips. I will call them to unlock the option to order more. I physically cannot just request because I do it online and the option to request them is locked.

 

[Jaylee]

I am using online repeat prescription system from my GP and an option to request test strips (test cassette) is greyed out. It says next available request is at date xxxx. " Last Issued: 11 Jan 2021 Cannot order medication until 14 Apr 21" I think I can order 100test every 3 months or so, which makes it around 100days for 100 test strips. I will call them to unlock the option to order more. I physically cannot just request because I do it online and the option to request them is locked.

Hi,

That sounds like the Accu-Chek Mobile? (I use the mobile.)
That's interesting. I've not had any issue either online or using the paperwork.
My repeat does 200. I just order as & when. Same regarding any of my meds. If I was to to order the lot, I'd have too much of one thing & not enough of the rest.

I try not to over complicate things with my lot.

 

[searley]

I’m legally required to do tests using a regular glucose meter I often do 8 or more tests a day

So get a good change to compare with libre/Dexcom

My go does not limit my test strips I get 150 at a time and cen request more than 1 lot a month