Before the Dexcom 3 and Libre 3 came out, I was switched by my provider to the Dexcom 6 from the Libre 2, cause the Libre 2 was so inaccurate for me as to be useless. The Dexcom 6 is imperfect, but works well enough to give me the control I want. I am wondering, has anyone switched from the Dexcom 6 to the Libre 3? According to MARD ratings, the Libre 3 is better than the Dexcom 6, and even better than the the Dexcom 7 in terms of accuracy. But, as I pointed out in another posts, MARD is not super reflective of real world performance. So I am wondering about real world experience with the switch. My insurance is likely to approve the Libre 3 within the next six months or so, and it would be a lot less costly than the Dexcom 6. If it is super-duper accurate, great - but all I really need is at least accuracy equal to the Dexcom 6. Anyone made that particular switch form Dexcom 6 to Libre 3 and can give a report on their real world experience with comparing the two in terms of accuracy? If you are someone who had tried the Libre 2 and found it did not work well for you, that would be a bonus.
As a Tandem pump user, I am locked into the Dexcom 6 for the moment. According to my endo, the ability of Tandem to link with the G7 is about a year away.
It’s wise of you to ask for actual experiences. There’s some talk that the conditions of the test of the Libre 3 were designed to give an especially low MARD rating. Here’s an article that explains ways a MARD study can be structured to achieve low numbers: https://www.diabettech.com/cgm/lies-damned-lies-and-statistics-the-art-of-the-cgm-accuracy-study/
Yup. Shared articles on the flaws in MARD ratings recently. So definitely waiting to hear about real world experience.
One thing you can count on with all the large companies, i.e. MDT, Abbot, etc. Is that they have SMART statisticians and high quality study managers that work hard to show their products in the best light. One of these large companies (who shall remain nameless) learned an important lesson when they had a cool therapy not meet their primary endpoint because they shorted the clinical study team $500,000 after investing over a billion in R&D on the product. The result is that you get clinical study managers who are working hard to make sure they meet their endpoints…
One thing as normal people that can do things is mandate that your country do post-market studies like the ones being conducted in the nordic countries. We learn so much from those and the effort is so small compared to the huge effect they have on medicine…
Not a G7 or Libre 3 user yet. But I use both a G6 and the Libre 14 day or a Libre 2.
I use both at the same time because the Libre allows me to swim in the ocean for hours and scan my BG level while I’m swimming. The G6 won’t do that, it takes way to long to communicate raising it above the water line and just won’t at all in the water. The LIbre has been invaluable to me because of that. But it goes back into my purse as soon as I am done.
I find the Libre still to be about 25 points off most of the time. It works for me while I am swimming because i can watch for what I am trending. I just got done with 3 bad Dexcom sensors in a row, failing within 1-3 days. I have a feeling my phone ap got messed up somehow because I eliminated the ap from my phone and just used the receiver and the 4th sensor is working fine. But I used the LIbre as a backup while I went through the 5-7 days of my G6 sensors failing.
I think the Libre is great, I happily used it before I switched to a Dexcom. I relied on it when my G6 sensors were a problem, but it reminded me why my control got better when I switched to a G6. Sure you can say I will add 25 points to my numbers to dose, that’s what I used to do, over 90 it’s almost always off that… but sometimes it’s not. I did a lot of fingersticking during that time because I am used to more accuracy nowadays. My fingers ended up sore like the old days.
When cost is a decision, the Libre works. But if you don’t have to factor cost the Dexcom is better because you can calibrate it. The Libre 3 you can’t. The Libre accuracy didn’t improve that much with the Libre 3. I thought there was one measurement where the Libre 3 won over the Dexcom, But the Libre 3 MARD score is from Abbot’s website. But they are all pretty close anyways. But yes, I’m sure they measure in a perfect world to get the best results.
Dexcom G6 MARD 9%
Libre 2 MARD 9.3%
Libre 3 MARD 9.2%
Supposedly the G& is 8.7% I believe. I didn’t find that on their website though.
But for me it’s all about the fact that you can calibrate a G6. Without the calibration I’ve had my G6 off 90 points when I start it or 90 points the next morning when it had started off being closer in accuracy and I left it alone. But because of the ability to calibrate it, the Dexcom system is far superior in my opinion. Until you can calibrate a Libre, I think that will hold true with the new versions.
But I have not used a Libre 3 or the G7 yet.
My problem with the Libre 2 was not only that it was highly inaccurate in scale (large difference from finger pricks.) For me it was inaccurate in direction, showing blood sugar rises when my sugar was falling, and drops when my sugar was rising. That made it completely useless. I agree that calibration is essential with Dexcom 6. I ignore it during the first three hours after warmup (swings too wildly for calibration to make sense) then do a first calibration after that. I usually do a second calibration that evening, a third at the 24 hour mark, and calibrate once every 24 hours thereafter. It is usually within 20 points after the 2nd calibration, and is about double the accuracy of the 20/20 rule after 24 hours. (That is after 24 hours it usually within 10% of any finger prick over 80 and within 10 points of any under 80. )
One good thing about the Libre 3 is that even though it does not require calibration it allows it. If you go to this Abbot page you will see the usual boast about “no finger pricks,” with a non-linking reference to footnote 3. Since there is no internal link to footnote three you have to scroll way down to read the following: “3 Fingersticks are required for treatment decisions when you see Check Blood Glucose symbol, when symptoms do not match system readings, when you suspect readings may be inaccurate, or when you experience symptoms that may be due to high or low blood glucose.” You can actually calibrate by user unfriendly means of logging your blood sugar, and then choosing a sub-choice that tells the libre to use the value to calibrate. I’m not sure if this is native to the Libre app or only available through some third party apps.
OK it turns out that a third party app that could calibrate the Libre 3 stopped working after a Libre 3 update. So currently the Libre 3 still cannot be calibrated, even with 3rd party apps.
Is the Libre 3 a flash Glucose Meter (FGM) or a CGM now. I know 1 was becuase I wore one and hated, believe I also wore the Libre 2 also, just as bad dug the wear time was longer.
The Libre 3 is a true CGM like Dexcom. It automatically sends a glucose value to your phone app (no reader yet) every minute. I was on Dexcom G6 for several years and found it very accurate, although I occasionally did have to calibrate it or had a bad sensor. Now I am on the Libre 3 but have only a couple of months experience. What I have found so far is that the Libre3 is reasonably accurate when my glucose is above 100 mg/dl but reads much lower than finger sticks when my glucose is below 100 (sometimes 20-30 mg/dl lower and causes nuisance low alarms). However, I am quite lean and am wondering if part of the inaccuracy is sensor placement on the back of my arm so will need to try to find a spot with more subcutaneous fat in case that affects the Libre3. It would be best to hear from more people before giving much credence to my limited exerience (3 sensors so far).
Hi GarLipow,
I don’t have any experience with the Dexcom, but I did switch from Libre 14 day to Libre 3. I switched because I needed the alarms because of low glucose at night. I have found that the accuracy of the Libre 3 is vastly improved over the Libre 14 day. The change is mostly in the algorithm is better. I have more accurate numbers and I am getting a better idea of exactly how many carbs I need to prevent/correct low BG.
I don’t know if this is what you need, but I do hope it helps.
All data is good, Michael.
I had one other thought about the Libre 3 sensor. If you go on the Libre website, they have an offer for you to try one for free. I don’t know if this offer is available outside of the United States or not.
YOu need to go sign up for the offer, and they email you a coupon to get one sensor free from your pharmacy. You will need a prescription from your provider for one sensor. Tell the pharmacy that they should only use the code on the coupon (if they try to bill your regular insurance first it will cause problems). This gives you a two week trail that will let you wear both and compare.
Good Luck.