Issues with Freestyle Libre

How and where are you installing the sensors? I don't want to suggest that your issues are caused by user error, but that's certainly what causes many of these failures/inaccuracies.

I have used 5 sensors since November.
Have 'calibrated' each one against finger prick tests using Freestyle Neo strips in the Libre.

Sensor 1 tested consistently 0.5-6 mmol/l lower than the prick test
Sensor 2 tested consistently 0.3-5 mmol/l lower than the prick test
Sensor 3 tested consistently within 0.1-2 mmol/l of the prick test
Sensor 4 tested consistently 1-1.2 mmol/l lower than the prick test
Sensor 5 tested consistently 0.1-2 mmol/l higher than the prick test

I was happy with all of those (I know I am not on insulin, but all but sensor 4 were well within a comparable 15% +/- range expected from prick testing meters, and even no 4 was highly consistent).

All 5 sensors were less accurate within the first 2 days and the last 2 days of use.

Am quite sure that I will hit a dodgy sensor soon, but so far I am DELIGHTED with the Libre and go into a minor period of mourning when I remove a sensor. I am limiting myself to 1 sensor every 3 weeks, to prevent total dependency.

I am wearing them, as intended, on the back of my arm, which is 'well padded', and nowadays I apply the sensor 48 hrs before activation since that seems to help with accuracy early in the sensor's life.

kzlorenz said:

Is there any pharmacovigilance agency in the UK that oversees this kind of things ?

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There's the Yellow Card Scheme:

http://www.nhs.uk/chq/pages/1962.aspx?categoryid=73&subcategoryid=103

I have been using the sensor for 6 months now , it must be noted you are measuring 2 different substances one being blood glucose via finger prick and the other being Interstitial fluid glucose via Libre so they will vary sometimes more than others so its always advised if too low or too high to do both checks..there is definitely a disparity between the measurements but seems to be when too high or too low can go either way...I only wear it when I need to give my fingers a rest as I test a lot.

Without checking back through my account, I couldn't quote how many sensors I have had replaced, but it's a proportion of them.

I obviously don't have Abbott data to look at, so any statements I make can only be my reasoning (which may be extremely flawed) or a plain old guess, so make if it what you will.

Firstly, I love the Libre. I was already in a decent place, diabetese-wise, before I started using the Libre, so it hasn't made a material difference to my control or HbA1c scores, but it has given me insights into situations I would never have appreciated without it. By that I'm thinking about delayed rises, impacts of lots of protein, the impacts of stress and/or being under the weather, and of course, what happens when we are at slumber.

However, on the downside, the sometimes frailty of the odd sensors is frustrating beyond measure. I have spent a fair amount of time preparing for and making calls to Abbott in order to give them decent, focused, accurate feedback.

I am pretty certain that my own blood profile, which runs pretty low and on very tight tracks, doesn't help with the Libre, in that a difference of 1.5 could be absolutely material and outside meter tolerances, so that will potentially be an issue in terms of ongoing use, not to mention my own acceptance of the variances. I like accurate data. Ahem.

I am also incredibly slight and have no padding whatsoever. My body fat percentages are very low, which I have asked about. Abbott tell me this is not an issue in terms of the device capabilities, and I can see that as it is approved for use for minors, they could also have little body fat present (due to their little limbs ).

I'm rather hoping that when some competition enters the market, and I can't see that being eons away, there will be some price point competition along with it, which may influence either a trimming in price or periodic offers. Whilst they have 100% of the market, there is no commercial incentive for Abbott to do that.

Look, let's be honest about this. The yellow card scheme is there for faulty devices. CGM sensors, by their very design, are subject to issues and manufacturing problems. I've used the Libre for 18 months and had my fair share of variance on readings that I got Abbott to replace, but I don't think there was a yellow cardable fault per se.

It is exactly the same as faulty sensors on Dexcom and Medtronic systems and I'm certain that those don't get yellow carded. Even the manufacturer says that if the sensor shows low or high, it should be followed up with a blood test and all the advice is NOT to medicate using the readings.

It sounds as though you may have had a faulty batch of sensors, and sadly these things can happen. It is in Abbott's interests to get this right because if they can't they will never make it on to prescription.

I personally don't think that we should be wasting public sector time investigating issues that the manufacturer knows about and is trying to fix, especially given the use case described earlier.

But it's up to you if you want to.

tim2000s said:

Look, let's be honest about this. The yellow card scheme is there for faulty devices. CGM sensors, by their very design, are subject to issues and manufacturing problems. I've used the Libre for 18 months and had my fair share of variance on readings that I got Abbott to replace, but I don't think there was a yellow cardable fault per se.

It is exactly the same as faulty sensors on Dexcom and Medtronic systems and I'm certain that those don't get yellow carded. Even the manufacturer says that if the sensor shows low or high, it should be followed up with a blood test and all the advice is NOT to medicate using the readings.

It sounds as though you may have had a faulty batch of sensors, and sadly these things can happen. It is in Abbott's interests to get this right because if they can't they will never make it on to prescription.

I personally don't think that we should be wasting public sector time investigating issues that the manufacturer knows about and is trying to fix, especially given the use case described earlier.

But it's up to you if you want to.

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As always, the voice of common sense.

I think part of our issue is that we are at the forefront of this style of monitoring. I bet finger prick meters were a bit iffy when they were first developed too.

We can either join in now, or wait until later, when some of the wrinkles have been ironed out, but I'd rather crack on, understanding my condition today, and accept that nothing's perfect. We'll never achieve perfect in this arena.

kzlorenz said:

Thanks for your reply.
I have been on the phone with ADiabetes Care several times and I am under the impression that Abbot is trying to keep this a bit silent...

FYI in EU the Freestyle Libre is now prescribed for children 4-16 and paid by the national HS.

I am a big fan of this device but I was expecting a more proactive way to deal with these inconveniences.
I also think it's our duty to inform the authorities of a potential big problem. I have let Abbott know about my intentions and if the want they'll have all the chances to deal with this themselves.

Cheers

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That isn't quite my understanding, although I would be delighted to be wrong, on this one.

My understanding is that the Libre has been approved for use on children, as opposed to the initial release which was approved for adults only. The approval for prescription is a different approval loop.

As I say, I would be happy to be wrong.

AndBreathe said:

That isn't quite my understanding, although I would be delighted to be wrong, on this one.

My understanding is that the Libre has been approved for use on children, as opposed to the initial release which was approved for adults only. The approval for prescription is a different approval loop.

As I say, I would be happy to be wrong.

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I'd agree. It has received EMA licensing for adults and children from four years old. It has not been approved by local healthcare providers on a Europe-wide basis. It is available for adults via healthcare plans in Sweden and Germany I believe.

Diagnosed type 2 last year and I started using the libre freestyle sensor kit very recently. The first two sensors, which I fitted carefully and following manufacturer directions, had to be replaced as they allowed water in whilst showering. I am on my third sensor in about 10 days and so annoyed about the situation that I have made a rubber cuff from rubber gloves with Velcro fasten in order to keep the sensor dry whilst showering! I am hoping this will solve the problem - has anyone else experienced water ingress? Of course I followed all the instructions to the letter but the customer service at Abbott said there were sometimes glue "issues". The information I see as I use this is valuable to me as I am type 2 and take 500 metformin XR once daily and hope to be able to get off that in time. This should help me do so if I can cope with the technical issues I encounter. I try to keep low carb high fat mainly.

I lost my last sensor in a hot tub (after repeated soaks). It was near the end of its 2 weeks.

This next sensor I slapped some Opsite tape over it.
Works like a charm.
Each piece of Opsite is lasting about 5 days, then peeling off and bing replaced.
Actually, the biggest problem it that the Opsite is sticking to the sensor so well, that I risk pulling it off when I peel the tape back.

Thank you B for your tip I just ordered some to try and I also saw a utube video about making a cardboard or similar template to get just the right shape cut out each time you cut out the film. That was someone with a continuous insulin monitor or pump I think but similar idea for fixing the item resiliently and not wasting tape.

BGW said:

I'm just into day 4 of using my Freestyle Libra system. However, I have found that there are significant differences between the readings supplied by the Libre to those of my trusty blood-glucose meter. I have run some tests and found that whilst the libre reported my blood-glucose levels 'over a four-hour period' to be consistently above 10 towards 11, my trusty glucose metre recorded my sugar levels to be around 7 over the same period of time. I am aware that there is a time difference between taking a glucose reading from a blood drop to one with your sensor. However, my tests were done over a four-hour period. This is extremely concerning, I had put my trust in your libre meter readings and started to adjust my exercise and eating to correct the high blood sugar levels I was being shown. I would also say over many years that I have been diabetic I can feel the changes in my body when my blood sugar levels are too high, these feelings never occurred, which again indicates to me the readings from my trusty blood-glucose meter to be correct. My blood-glucose meter has also been compared to the readings taken by my diabetic nurse and found to be almost identical to her meter. I paid a lot of money for the Freestyle Libre, and my tests show it to be wildly inaccurate and potentially dangerous for my health.

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Have you contacted the Abbott support line to discuss your finding with them?

BGW said:

I've used their on-line contact form, still waiting for a reply. I did note their extremely strick reader (meter) return for refund policy.

This is a copy and paste from their website.

Reader Open - Abbott is unable to offer any refund with respect to a reader that has been opened.

Basically, once you take it out the box your stuck with it...

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My interpretation of that Abbott statement is that if you received the reader, opened it, looked at it, then decided you didn't want it you would have trouble getting a refund, due to the open box.

The reader comes with a 2 year warranty, so if it is found to be faulty, they will be contractually bound to deal with it. In my experience I would say your issue is likely to be the sensor, not the reader.

The only time I tried to use the Abbott email system, the response time was very slow, (but within their contractual requirements apparently). Personally, I would always do my preparation, make the call and talk to them. If you have done your homework and can make your case, it's much better to talk to someone. At least that way you have a chance of understanding if the person you are talking to understands what you believe to be the issue. You don't get that immediate feedback in writing.

If you have done your homework in order to write up your issues, you've done the work for the call.