# Freestyle Libre - Sensor failure rate increasing?



## RascallyBear (Mar 14, 2021)

*Mod Edit:* This post and the responses were split away from an older thread: https://forum.diabetes.org.uk/boards/threads/freestyle-libre-sensor-failure-rate-of-40.71482/page-3



Derrick Baughan said:


> Has anyone else kept a track of the failure rate of the sensor?
> 
> I have just started with the system. A 'trial' where I was issued a reader and one sensor, at the hospital but by a company rep. Clearly not a trial in the true sense of the word. More a marketing ploy to create demand. Although there is nothing inherently wrong with that. I am now self-funding the sensors until my CCG (Cambridgeshire) approve the use.
> 
> ...


I've been using Freestyle Libre since 2018. So around 80 fortnightly applications. At first failures were few and far between. But from the tail end of 2020 through the first quarter of 2021, I'm getting frequent failures.

Mostly, the sensor that's meant to last 14 days actually stops working after 10 or 11 days. Because in some countries the sensors are programmed to last fewer than 14 days, I'm suspicious that this is a programming error. Either the sensor's firmware is being set to 10 days (as I think they do in the USA) or the android smartphone App is at fault. These failures are too consistent.

The other fault that I've begun to experience only recently is with the spring-loaded applicator. Until recently, the applicator worked perfectly. But over the past 6 months, I'll press the applicator firmly onto my arm, and then there's a hesitation before the spring works. It'll start to work, but then there's a pause before the needle fully goes forwards. Sometimes there's a complete hang-up, with the mechanism only working as I pull the applicator away from my arm. I'm actually a designer, and my impression is that the problem is indicative of a manufacturing error caused by worn out manufacturing equipment.

I'd be interested in others' experiences. Today, 13th March 2021, I had a sensor pack up 3 days early. Then, the replacement sensor applicator misfires, leaving me with a painful needle feeling in my arm. This 2nd sensor only lasted for 8 hours before giving a failed sensor message.

I'm highly suspicious that the NHS contract is creating a manufacturing problem for Abbot, and that we're being supplied with sensors programmed to last only 10 days rather that the NHS contracted 14 days. Also, that Abbot are using worn out manufacturing equipment, which is causing recently released applicators to misfire.

As for my satisfaction: well, the Freestyle Libre sensors have changed my life. I couldn't live without them. A brilliant system. Hopefully Version 2 will fix the problems.

Stay safe everyone -- Rick


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## daducky88 (Mar 14, 2021)

Derrick Baughan said:


> Has anyone else kept a track of the failure rate of the sensor?
> 
> I have just started with the system. A 'trial' where I was issued a reader and one sensor, at the hospital but by a company rep. Clearly not a trial in the true sense of the word. More a marketing ploy to create demand. Although there is nothing inherently wrong with that. I am now self-funding the sensors until my CCG (Cambridgeshire) approve the use.
> 
> ...


If they gonna send you some replacements, ask for them.to be from.a different batch.  (You can only try...)


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## daducky88 (Mar 14, 2021)

RascallyBear said:


> I've been using Freestyle Libre since 2018. So around 80 fortnightly applications. At first failures were few and far between. But from the tail end of 2020 through the first quarter of 2021, I'm getting frequent failures.
> 
> Mostly, the sensor that's meant to last 14 days actually stops working after 10 or 11 days. Because in some countries the sensors are programmed to last fewer than 14 days, I'm suspicious that this is a programming error. Either the sensor's firmware is being set to 10 days (as I think they do in the USA) or the android smartphone App is at fault. These failures are too consistent.
> 
> ...


Well its true that if sensor failure was a random event, then some sensors would longer than 14 days.
If sensor failure is random but with a programmed cut off at 14 days, then Abbott isnt providing a 14 day service on average, but something lower 
I would agree with you that the structure of the nhs contract might need alteration to incentivise Abbott to bring the average up to / beyond the 14 day average e.g. stipulating: 
The co shall provide a service of sensors which on average over a year will have a sensor functional life of not less than 14 days per sensor, or provide a proportional refund to the payer, whether NHS or patient.  Until mean sensor reliability reaches 14 days +- 5%, the co will provide each patient a rolling reservoir of back up of n sensors to expedite seamless service provision.


Something like that cut for whats its worth.  Howeved the NHS wont release the details but we could send a letter to NHS contracting, offering some thoughts.


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## helli (Mar 14, 2021)

@daducky88 as Abbott always replace faulty sensors whenever they fail, don't they already provide an average of more than 14 days per sensor the NHS purchases?


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## daducky88 (Mar 14, 2021)

Ljc said:


> Hello @RhiWJ  welcome to the forum.  I am sorry  to hear you are having problems with the Libre, what’s been happening ?
> 
> Some people use Tegaderm over the sensor to help keep it on, you need to cut a hole in anything you use to cover the sensor as the hole in the sensor is there to keep the skin under the sensor healthy and dry.
> Personally I don’t  cover mine with anything , I’ve just got very careful when going through doorways and place my sensor right round the back  of my arm which means I apply and swipe my sensor under arm rather than going over the top.
> ...






trophywench said:


> You seriously expect any commercial company to appraise a customer of the reasons for a failure?
> 
> I - seriously! - wonder what their own contract terms with whoever make them, is?  I've had to send a pump handset back twice cos they failed (same mfr, but different pumps) but as I had alternative glucometers in hand at the time, NP.   I had a pump failure too with my first pump - but a bit later they published an alert warning all users not to do something I'd been doing for ages, so I concluded that WAS the reason mine failed - but I've no idea cos they never tell me either.  Hence, you're not alone.
> 
> They have no idea whatever whether you, I or anyone else could make any trouble about it wherever we wanted to, do they!



I think the problem is one of structuring seamless service.  If your pump/ test kit fails on a Thurs night of Easter bank hol..., the contract is structured i believe so that that lack of seamlessness is probably covered a statement of get thee to A+E.  Great, when everyones on the ras.

This is a problem of unmet need for contingency.  Trying to get a prescription from my gp for a few manual syringes or a prescription of long acting insulin in addition to what i use for a pump is like going for a session with Spanish Inquisition or sitting in on Oliver Twist...More! You want more!  I 'm not sure how much variation there is between GP practises either.   Mine have the standard practise of not matching repeat prescription dosing to consultant's written records so its a tedious ongoing battle with them.  

I think a lot of the problem lies in the concept of applying a waste minimising strategy for temporary conditions to chronic conditions where small prescriptions maximise inefficiency, a cost.


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## daducky88 (Mar 14, 2021)

helli said:


> @daducky88 as Abbott always replace faulty sensors whenever they fail, don't they already provide an average of more than 14 days per sensor the NHS purchases?


Only if the replacement sensor is invariably available the instant one fails.  Does the co provide replacements for unreliable product cost free in each instance or only up to a limit?
Do sensors invariably fail in office hours or when one has back up stocks?

The problem with the NHS is removes barriers to service for acute problems e.g. if you chop you finger and go to a+e, they'll stick on, after triage....  If you dont run hospitalization extremes of blood sugar with diabetes, you carry the burden.  The concept of pumps without AI and sensors is like building a set of houses minus infrastructure or services. Sure, the shelters welcome.  But one does not have full freedom of manouevre.   The NHS and the state is stacking up future cost for through lack of access to glucohomeostasis for diabetics.  I'm not sure how much extra cost falls on the state from blindness and renal failure for haemodialysis(HD).  I think dialysis costs the NHS about £35k pa equating to an extra £175k per patient who transitions from T1D to T1D + HD.  I imagine the cost to other parts of state from blindness are considerable.
The chances of developing HD in a lifetime are 20% for a T1D in the UK.  So of 300,000 T1Ds, 60000 will potentially, require HD, although by the 5th yr post diagnosis at 13% pa transplant rate ~50% will have rcvd a transplant, making the average n of HD recipients across 5 yrs  ~4500O from T1D, incurring an extra of £7.9B over 5 years.
I guest the cost of supply 0.3M t1ds with seam ai enabled sensored glucohomeostasis would be:

Non ai non sensor pump £3k
Plastics 12x70x
x300, 000

Ai pump ~£10k
Sensor per month x12 x70 yrs x£100pm
Plastics pm x12x70x £
=£84000 lifetime sensor cost
= £94k pp for pump.+ sensor
X 300,000 patients
=£28B raw cost

For a non ai pump 
Of course with an ai sensored pump fewer people would go blind and req hd, 

I'd hv check that.


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## helli (Mar 14, 2021)

@daducky88 as with everything in our diabetes paraphernalia pack, everyone should have backups. So when a Libre fails, you put your backup on. This gives 14 days for you to contact Abbott and for them to send a replacement.
They have successfully done this for me 5 or 6 times without any questions, including when two failed within a week. I assume it was a dodgy batch.
I have heard nothing about them limiting how many they replace provided it is a genuine fail.

I don't think your NHS issues have anything to do with the Libre reliability.


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## DavidG89 (Mar 15, 2021)

I have had no issues with it coming off by itself, it's usually catching it on a door frame or brushing up against a wall (yes I can be clumsy). I do find that the sensor can either be massively wrong on highs and sometimes wrong on lows. For example I have had it showing 15mmol and rising but my blood glucose meter shows 8mmol and after I checked it half an hour later to have the Libra showing 13mmol and the blood glucose 7mmol. Also in terms of lows, it would regularly show between 3 and 3.5mmol but on checking blood glucose it has been 4.5-5mmol. if any of my readings are out with the range 4mmol to 10mmol I will double check and keep checking with my blood glucose meter to be sure.


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## everydayupsanddowns (Mar 15, 2021)

Sorry you've been having a rough ride with Libre sensors @RascallyBear 

In all the sensors I have run off and on, since 2014 I think I've only had one or perhaps 2 that didn't run the full 14 days.


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## mikeyB (Mar 16, 2021)

I’ve only had a sensor fail once, about 12 days in. Couldn’t be bothered telling Abbott. I’ve been using the Libre since it first appeared. I’m still self funding, mainly because it’s a sight more efficient, and the money is neither here nor there. 

The Libre 2 is much more accurate at low BG levels. The alarm on the reader woke me up in the night, and showed 3.2. Didn’t feel like I was 3.2, probably because it had been a gradual long drop, so I used one of my Optium test strips and used the reader as a normal fingerprick reader. Guess what the result was? 3.2.

The other result was eating four Jelly Babies and going back to sleep.


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## Bexlee (Mar 16, 2021)

I wouldn’t say increased failure rate but with libre 2 there’s a few more error / can’t read try in 10 min messages.

I’m 3 sensors in (to libre 2. Had libre 1 for just over 2 years)....1st sensor perfect. 2nd sensor kept losing signal to phone rang Abbott and faulty so replaced. 3rd sensor almost perfect, a few try on 10 min messages.

Abbott are good at replacing if you call them. 

Like @mikeyB says alarms good. Wake up double check jelly babies back to sleep


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## nonethewiser (Mar 16, 2021)

Not noticed more error messages, if anything less. Find it is more accurate, more so in range lower levels, less so at higher levels.


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## RobinFey (Nov 1, 2021)

We have had  3 sensors fail eithers shutting down early or not even starting up. The last 2 i picked up today the needle fell out of one and the other didn't even have a needle in. Also there was a sensor stuck to the bottom of the box. That's £350 the NHS has spent. I have tried to inform someone to report the drop in quality but know one seems interested. I don't want to have to keep on calling Abbot for replacement i just want a sensor that works the first time.


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## MikeS (Mar 16, 2022)

RascallyBear said:


> *Mod Edit:* This post and the responses were split away from an older thread: https://forum.diabetes.org.uk/boards/threads/freestyle-libre-sensor-failure-rate-of-40.71482/page-3
> 
> 
> I've been using Freestyle Libre since 2018. So around 80 fortnightly applications. At first failures were few and far between. But from the tail end of 2020 through the first quarter of 2021, I'm getting frequent failures.
> ...


I’ve been using Freestyle continuously since October 2016. A couple got knocked off but only two failed recently after 2 days. The ones that lasted all lasted 14 days. Never less. So maybe the phone app is the problem. I always use a Freestyle reader.


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## rebrascora (Mar 16, 2022)

MikeS said:


> I’ve been using Freestyle continuously since October 2016. A couple got knocked off but only two failed recently after 2 days. The ones that lasted all lasted 14 days. Never less. So maybe the phone app is the problem. I always use a Freestyle reader.


I always use the reader but I am still using the original Libre 1 and I do wonder if the current problems are with the Libre 2 manufacture or algorithm. I am happy to stick with Libre 1 and my reader as they both work very well for me and I don't need the alarms.


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