Freestyle Libre 14day accuracy?

Hi

I’m thinking of changing over from the disappointingly inaccurate freestyle Libre 10day to the 14day.

How accurate do you find the 14day to be?

Does anyone know - is Abbott labs phasing out the ten day model?

Thanks as always!
Eric

My wife is on the her 2nd 14 day after using the ten day

Has been tracking decently with a countour next meter - happy with the first 2

initially the ten day were a horror story - stated 2/2018 - almost gave up!

the last 5 months have been good to very good

saved a lot of lows -

I still have 3 sensors left that are 10 day so I am hoping the 14 day sensors will be more accurate.

I gave up on paying attention to the “numbers” from the Libre but I do like the graph and seeing direction.

Next month I will start the 14 day. Sure hope it is better.

I had the Libre for 3 months but it was way too inaccurate, 30 points off on average and at times 80 points. Tried the Dexcom and it worked. Had it for a year and every sensor (lasts 3 weeks to 4 weeks) is within 6% even better than they promote. Plus it alerts me when BG is too high or low (I set the alarm numbers) which is especially good at night. And readings change every 5 minutes without swiping. And you can place it anywhere so it is out of sight. Hated swiping my arm in public just to get a reading. More expensive than Libre but if that is not an issue, I highly recommend.

Dexcom now covered by Medicare. I was interested but it is not yet available to Advantage plan patients.

Will continue using Libre until I can get Dexcom.

Is there a difference in price, 10 vs 14 days? How much do they cost?

2 sensors of the 14 day libre cost the same as 3 sensors of the 10 day. I pay $75 per month at CVS with a discount coupon.

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Its my second 14 day sensor. First one quit working at 10 days. Called Abbott and they replaced. Very helpful. First sensor was accurate. Second sensor was off to the high side. Questions are being raised, is it the sensor or reader that’s incorrect. Easy fix! Download the app to your phone and compare the readings. If it is the same as the reader there’s your answer. Its your sensor that off. I would just add or subtract your finger stick to your reading or call and complain to Abbott. They will replace. Also make sure you wipe your arm with included wipes to remove any contaminants on your skin. Switch arms and/or locations and experiment for best results. Quit happy so far with this product and I believe if Abbott gets enough complaints about accuracy it will help them improve the product. After all, not sure if they want to keep sending out free sensors.

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My wife uses it and it is very satisfied - initially when she started about 2 years ago it was a disaster for the first three months to the point I almost threw the reader in the trash - then something must have changed because the last 18+ months it has been excellent - especially on the low side. Saved a ton of problems. Abbott just replaced the reader no charge after a year of use. Looking forward to the T2 if the FDA ever decides to do it’s job.

I used both, 10 day a few months, then 90 day supply of 14 day sensors from supplier. My impression is they might each have at least a 15/20% error rate, not much different from the finger testing varied systems I used many decades. I think in time it moves closer to an accurate number, but I am not sure the error rate is any worse than finger stick sys.

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My wife last 9 readings - countour next/reader - morning only

101/110
103/107
78/74
160/154
78/92
54/58
45/55
140/140
82/93

Freestyle is as accurate as decom if you use the tomato app and or xdrip. These apps allow you to calibrate the 14 day and 10 day sensors. Most people that complain about the factory calibration are using abotts Factory app. This is configure to run always with a delta. dexcom continues to benefit from this issue as people dont try to go outside the freestyle app. You can save a ton of money by going freestyle. If you need bluetooth you can get miao miao or other adapters for the libre. I use the libra with miao miao as a blutooth to my phone to androidaps for DIY insulin pump.

My G6 sets me high for about a day and a half and then settles down for the rest of the 10 days run. When I was on the Freestyle 14, I was usually given a number that was consistently about 15-20 pts low but the tends were trustworthy. Caveat… I don’t calibrate, which would probably fix the Freestyle issue if not also the G6.

The new Freestyle Libre 2 (with high/low alarms) has been approved by the FDA. Abbott says it will be the same price as the Libre 14 Day.
Does anyone happen to have switched to this new Libre, yet?
My doc said it wasn’t in his “system”, yet (as of last month), but I’m going to have Walgreens give ordering it a try when I get a refill soon.

@dogramma I’ve used it. It’s the same price with a discount coupon from Abbot for use through December, otherwise it is more expensive. $37 at Costco for 14 Day Libre, $60 at Costco for Libre2 (both are 14 days, they just needed another name).

You can set the low alarm down to 60 and the high alarm up to 400. Costco either has it or got it in within a day. It’s supposed to be more accurate, but it didn’t seem any different from when I used to use them. I just got through wearing a couple of the Libre2 at the same time as I wore my Dexcom as I wanted the Libre for snorkeling. works great for snorkeling.

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Hello, I have been using 14 day libre for a year and a half now, the readings, compared to my Prodigy test strip meter, are always 20-30 points off; every once in a while the are more accurate. I have learned to live with it. What do I like about the 14 day?, the tendency info. and the test frequency. I really wish it were more accurate. I live overseas and do not come to the US as often as before for obvious reasons, so I usually buy 6-10 months in advance hoping the expiration date is no problem. Is there an easy to fix the accuracy problem, being 20-30 points off always, seems to me that calibration will solve the problem. Thank you for your advise.

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Hi - I’ve been using the Abbot Labs Freestyle Libre since it was a 10 day unit. I spent maybe ten days taking my blood sugar twenty or thirty times a day and comparing it to the Freestyle libre. I dumped it into a spreadsheet and tried to see what kind of correlation there was between interstitial glucose levels as read by the Freestyle Libre and my blood glucose. Here are my conclusions

  1. My interstitial glucose changes about 15 minutes or so after blood glucose. There is a delay. That makes sense and seems organic and not related to the Freestyle Libre device;

  2. The difference in the curves is non-linear. The closer my blood sugar was to 100, the more accurate it was. The farther away from 100, the greater the amount of difference between the two readings (corrected for the 15 minute delay);

  3. The amount of geometric variation between interstitial and blood glucose was the same for a given device, but different between devices. One device might read 1.10X and another device might read 1.20X. I never got two devices from the same lot number to know if it is device dependent or lot dependent. I’m going to bet all devices in a given lot have the same geometric variation.

  4. Each device seemed to have its own unique linear inaccuracy - a fixed amount it varied from the others. So if my blood glucose was 100, device A might read 80, device B might read 75, device C might read 78. This was a translation in the variation - every reading on that device was off that much, plus the accuracy variation described in number 2, above;. The variation was always negative and always more than 10;

  5. So for each device I could calculate a formula that looked like mX+b=c. The first value was the variation described in number 3 above and b was the number described in number 4 above. 1.15*(blood glucose) -25 = Freestyle Libre reading. It wasn’t perfect, but it was pretty close.

  6. In researching glucometers, the FDA allows a shockingly wide variation in accuracy. I spent a week in that research before I picked the device that (at the time) had the best accuracy. The test strips are significantly more expensive than others. That leads me to believe there are different technologies for determining blood glucose. Some are more accurate than others. I also think the less expensive ones are less accurate. I bet Abbot Labs is using the same glucose detection technology in interstitial glucose they are using on the blood glucose glucometers, and their meters are not (at the time I looked at it) all that accurate. I bet Abbott Labs glucose detection technology isn’t that good, and that is a reason we see all the variation we do.

My conclusion is that the numbers are really meaningless because of the accuracy variations. I would never use this device if getting numbers were a priority. For example, if I were a Type 1 diabetic, I would never consider this product, nor would I consider Abbot Labs glucometers because of their inaccuracy. There are more accurate products and a Type 1 might want that kind of accuracy.

I use the device to look at the curve. I spent a month thereafter trying different foods and seeing how they affected the curve. I learned a lot from that. It tells me when I’ve eaten something that (surprise) had a bunch of carbs or sugars in it. It tells me when I’m crashing. I watch the first derivative of the curve, for those that remember Calculus.

I continue to use it because it provides me with reports I can take to my doctor. I can say - treat THIS patient, not a random patient on a normal distribution. I have changed doctors because they said - well, most patients do this, this is what it means for most patients. I have data that they can use to treat ME, not someone on a normal distribution, or on average. No one is average and when they treat that generic average patient instead of the patient in front of them, they are being lazy and I don’t want to do business with them.

Since using this device, and learning what to eat and what not to eat, my A1C went from 7.3 down to 5.3. I lost nearly 30 pounds. Yeah, I’m going to continue to use the device, but I know what its REALLY telling me.

Hope you found that entertaining. I’m no math major - I took calculus in high school many decades ago and do not use math in my work. Its my life and its important enough to do the research, in my opinion. Best Wishes!

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I understand the pressures doctors work under and I think the system (in the US, at least) maintains unreasonable expectations of them. Having said that, they should easily understand that we patients don’t want to be treated like some interchangeable commodity. Our metabolic profiles vary across a spectrum and these variations are unique enough to demand treatments refined for us personally.

Like you, I have learned a lot about my glucose metabolism from using and thoughtfully monitoring my CGM readings over many years. But I have given up expecting my doctors to practice with the ideal described above.

I now accept that my knowledge about my metabolism far exceeds what they will ever know about me. I don’t really need their advice but it is nice when their observations line up with mine. The most critical thing they can do for me is support my ongoing need for insulin, pump, and CGM supplies.

It feels demeaning on my part to simply see my diabetes doctors as Rx writers but that is what has evolved. I accept that reality and it makes it easier to interact with my doctor.

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Gosh, what you are saying is the sad fact in my experience in the USA. I kept changing doctors until I found one that was fascinated with the data I was providing. She said that data helps her treat me far more easily than guessing at what might be happening. She said most diabetics don’t keep track of what they eat and so they bring nothing concrete to the visit but their impressions. She said having data like I provide makes a huge difference in what she decides. I’m sticking with her. :slight_smile:

After re-reading my lengthy message, it occurs to me I’ve got something wrong. The formula is REALLY mX^Z+b=c. The variation in item three is an exponential variation, not geometric. I don’t know what the variable M is, but Z is that variation I talk about in number 3. Sorry for that.