My Trial of the New Abbott Freestyle Libre 3

There are many compelling features on the new Abbott Freestyle Libre 3 and I may decide to switch; but I may wish to first try the new Dexcom G7 once it's FDA-approved. But I won't wait forever...

In my 15 years of writing this blog, one thing I have never done is something I occasionally see some younger, less-discerning members of the blogging community do: which is to pimp their blogs (and themselves) out to receive free so-called "blog-ola". I've been blogging since 2005, and I have never endorsed a product in order to get free things, nor have I ever used my blog to even solicit free stuff from companies which aim to market their products to the autoimmune Type 1 diabetes (T1D) patient community by using me as an "influencer". I tend to view myself as more of a journalist covering the T1D space rather than someone blogging to get free $#!t.

Still, I very recently had what I consider to be a most unusual opportunity: to "test drive" the new Abbott Freestyle Libre 3 CGM for six weeks, which was formally FDA approved on May 31, 2022, just ahead of the ADA's 82nd Scientific Sessions which took place June 3–7, 2022. See Abbott's company press release about the FDA approval at https://www.prnewswire.com/news-releases/abbotts-freestyle-libre-3-receives-us-fda-clearance--features-worlds-smallest-thinnest-and-most-accurate-14-day-glucose-sensor-301557561.html for detail). I also wish to extend special thanks to my friend Riva Greenberg http://diabetesbydesign.com/ for introducing me to people at Abbott to make my Libre 3 trial possible!

 

 

 

 

 

 

 

 

 

 

In May 2022, I blogged about the formal FDA approval of the new Freestyle Libre 3 CGM at https://blog.sstrumello.com/2022/05/abbotts-freestyle-libre-3-finally.html if you're interested in reading my coverage of the FDA approval for the product), and at one point last year, I also seriously considered switching to the older Freestyle Libre 2 model (catch my post at https://blog.sstrumello.com/2021/06/should-i-say-adios-to-dexcom-g7-hello.html for that) due to my utter frustration with Dexcom.

At the time I wrote about thinking of switching to Libre 2, I was incredibly frustrated with my Dexcom G6 having repeated "signal loss" errors on brand-new sensors which pissed me off considering the prices they charge for CGM sensors, and a lack of instruction on how to fix the problem. But switching to Libre 2 meant a convoluted process to get the alarms and data-sharing which I considered a necessity. Ultimately, I resolved my Dexcom G6 "signal loss" issues on brand-new sensors by calling Dexcom's tech support to complain.

The recommendation Dexcom provided me actually worked; they told me to power my iPhone off, wait for 5 full minutes, and then power it back on again. Voila: no more signal loss messages on brand-new sensors. Still, that persuaded me to consider becoming a defector to a rival product. My impression as a patient is that Dexcom no longer really values my business very much as the company once did; the company presumes my business will always be there for them, and I don't believe they can afford to do so; as their product is far from perfect. 

The new Abbott Freestyle Libre 3 is now formally available in the U.S., though as I write this, the company is still mass-advertising (via costly TV commercials) the older Libre 2 device which requires scanning for wearers to get a reading. The ads for Libre contain messaging clearly aimed at Type 2 diabetes patients who simply don't like fingerstick testing. Of course, insurance company payers don't really care about whether patients like it or not, but that's the direction both Abbott and Dexcom are now pursuing: to try and convert many Type 2 patients into CGM users. Whether they can successfully persuade insurance company payers on that remains to be seen; the results have been mixed so far. 

Abbott Officially Launched Freestyle Libre 3 in U.S. During Q3 2022; Medicare Forecast to Launch in the Second Half of 2023

In Abbott's Q3 2022 quarterly earnings release, the company told investors "we initiated the full [U.S.] launch of Libre 3". In the investor Q&A following the Q3 2022 earnings release, Abbott CEO Robert Ford also told a Wells Fargo analyst that CMS/Medicare introduction for Libre 3 wasn't expected to happen until the "second half of 2023", although he added that commercial insurance will definitely happen sooner. Abbott is planning to pursue the pharmacy benefit model as the primary means of distribution, although it will also be sold on a more limited basis via DME suppliers, much like it is already doing with Libre 2. Rival Dexcom has an identical commercialization strategy, having migrated most of its sales to the pharmacy benefit channel.

As noted, I recently had an opportunity to test-drive the new Freestyle Libre 3 model for 6 weeks. Abbott invites patients on its website (see https://www.freestyle.abbott/us-en/myfreestyle-freestyle-libre-3.html for details) to arrange a free trial of Libre 3. The disclosures says "Eligible patients will receive one [1] FreeStyle Libre 3 sensor for users with a compatible mobile phone operating system at $0 copay. The expiration date of the voucher is 60 days from the issue date. This program is available for patients with Type 1 and Type 2 diabetes; it is not available for patients with gestational diabetes." Still, I highly recommend doing a trial if you can arrange it. Two weeks (the life of a single Libre 3 sensor) gives you a pretty good idea of what its like to wear it on an ongoing basis. That also gives you an opportunity to actually try the Libre 3 as opposed to hearing about it from a third-party like me.  

For me, the automated alarms and data sharing were the main reasons I stuck with Dexcom's CGM devices as long as I did, but now that Freestyle Libre 3 has those exact same features as well, the reasons for sticking with Dexcom are no longer quite as compelling (for me, anyway) as they once were, plus there are a few very compelling reasons to consider switching. Read on for more about my experience.

Abbott Is a CGM Giant; It Is Even Bigger Than Dexcom

Also during its Q3 2022 earnings release, Abbott told investors that the company's Libre CGM now has an installed user-base that was disclosed as "approximately 4.5 million" people globally. That means that Abbott (not Dexcom) is the worldwide market leader for CGM's (Abbott is significantly bigger as a CGM-maker than rival Dexcom in virtually every other country except for the U.S.). European users with diabetes seem to have adopted Libre, and Abbott has captured their business since they beat Dexcom to the Continent (betting that securing business from patients with universal healthcare coverage was a smart move, and it was for the company).

Rival Dexcom has attempted to limit the Abbott competitive threat in the U.S. market for Automated Insulin Delivery ("AID") systems in the U.S. For example, Dexcom has signed partnership deals with nearly every insulin delivery (pump) company, including Medtronic, Tandem and Insulet (although Tandem and Insulet also signed deals with Abbott; so they seem to be CGM platform-neutral; meaning Tandem and Omnipod users will eventually be able to use whichever CGM they [or their insurance] prefers).

Right now, many newly-diagnosed patients tend to rely upon AID systems more than longer-term patients. If I'm being frank, diabetes long-haulers like me (I will mark a half-century living with T1D in 2026) are simply more conditioned to using the crappier, older diabetes tools). Don't shoot the messenger; that's just a reality.

Libre 3: European AID Systems First, Then U.S. AID Systems

Abbott Freestyle Libre 3 was not initially cleared with the U.S. FDA for use with AID systems. I believe that path was pursued so Abbott could start selling Libre 3 in the U.S. sooner. Libre 3 is, however, already cleared in Europe for AID systems, which means the company could subsequently attain that regulatory clearance with the U.S. FDA at some point in the future by using the data from its European AID integrations without significant difficulty or delay. In the company's Q3 2022 earnings release to investors, CEO Robert Ford said "We are working on pump integrations outside the United States and we will have a pump integration launch by end of this year, beginning of next year into Europe with one of our pump partners and I think they are going to benefit a lot from our user base that we have in those countries."

Sure enough, on November 28, 2022, Switzerland-based Ypsomed announced that its mylife Loop AID system (with CamDiab's CamAPS FX and Abbott's FreeStyle Libre 3) had formally launched in Germany (Europe's largest diabetes market), with more European launches (and iOS compatibility) to follow in 2023. That partnership doesn't mean very much to U.S. patients right now, other than Abbott can use the data from the Ypsomed European AID deal when seeking U.S.FDA approval for an AID system. 

Ypsomed is a big player in the diabetes space. The company also has a collaboration with Lilly on its Tempo smart insulin pen systems (see https://www.lillytempo.com/ for more details), which is designed to be a competitive response to Novo Nordisk's NovoPen 6 & NovoPen Echo Plus, both smart-pen systems (see https://www.novonordisk.com/our-products/smart-pens/novopen-6.html for details on that) will reportedly work with Freestyle Libre 3. Branded insulin-makers are migrating to similar smart-pen systems to the Medtronic/Companion Medical InPen https://www.medtronicdiabetes.com/products/inpen-smart-insulin-pen-system system; a rival product is Bigfoot Biomedical's Unity system, but Bigfoot has a strange business model. Smart pens have been a bit slower to catch-on in the U.S. That said, since I was forced to use Novo Nordisk insulin by my insurance company (I opted for Fiasp), I have been an InPen user and I enjoy having the data on insulin on-board. I have also learned that I can use my InPen with vial and syringe injections simply by going into InPen's "Logbook" menu and manually logging a dosage, enabling tracking of my insulin on-board even without using the more costly Fiasp Penfill cartridges.

Anyway, on the previously-announced Abbott Freestyle Libre partnership with Insulet to incorporate Libre 3 into Omnipod 5, that doesn't appear to have gone anywhere ... yet. However, I suspect the reason is because Abbott was simply opting to delay that combination until FreeStyle Libre 3 had become very widely available in the U.S., which is happening now. I'm also unsure where the Tandem collaboration deal stands now.

Then, there's also Abbott's Libre collaboration with Bigfoot Biomedical. Bigfoot's Unity https://www.bigfootbiomedical.com/bigfoot-unity system is already FDA-approved, but I don’t believe its insulin pump is approved right now. Bigfoot has a very unusual commercialization strategy called "Bigfoot Clinic Hub" which requires doctors to subscribe to in order for them to prescribe Bigfoot AID systems to patients. Unfortunately, a large and growing number of endocrinologists and other doctors today actually now work as employees of large corporate entities (such as big hospital chains; including my own endo as of a few years ago), which means they cannot offer their patients Bigfoot products simply because their patients want them to; those decisions are managed by accountants within the organizations, not by doctors. Bigfoot may need to reconsider that strategy at some point.

I believe OpenApps https://openaps.org/ systems are also currently only coded to work with Dexcom because that was all that was available, but it seems likely that someone will eventually modify the OpenApps software to work with Abbott Freestyle Libre 3 as that CGM officially becomes widely-available in the U.S., which is happening now. The entire idea behind OpenApps is very much a DIY model, so it seems someone will eventually write code for Abbott Freestyle Libre 3, especially considering the Abbott CGM's much lower price-point (30% cheaper than Dexcom).

In other words, it's uncertain Dexcom's early-lead (and monopolization) of U.S. AID systems is necessarily a long-term impediment to Abbott's eventual entry in the U.S. AID space (I don't know how many of the Dexcom partnerships were exclusive; but, the market will ultimately be forced to accommodate the demand from commercial payers and patients on the market), so for now, Abbott is focused on the European AID space.

That acknowledged, as I already noted, my friend Riva Greenberg sent me (and a few others) a personal email indicating that if we were interested in trying the new Freestyle Libre 3 model, that she would put me in touch with a contact at Abbott who could facilitate a trial of the new Abbott Freestyle Libre 3 CGM system. I was interested in trying the new Freestyle Libre 3 model, so I said yes!

Abbott then sent me several documents for me to read and sign, as well as a letter to my endocrinologist requesting that they formally "prescribe" the Abbott Freestyle Libre 3 to me (Abbott advised me that particular part tends to take the longest to facilitate, so I wrote a snail-mail to my endo explaining that I was given an opportunity to try the newly-approved device and asked her to prescribe it to me to enable the trial). I also had a quick phone conversation with Abbott about the trial itself, but the interaction was very limited.

 

Fast forward a few weeks, and Abbott sent me a 6-week supply (3 sensors; remember each Libre 3 sensor lasts for 14 days, hence three sensors was designed to last a total of 42 days, which is about 6 weeks) of its brand-new Freestyle Libre 3 CGM. Since I was traveling in Europe just days after they arrived, I didn't want to deal with the unexpected and unknown while traveling, so I stuck with Dexcom G6 during my travels, and then it was Thanksgiving when I returned, so I didn't try the Libre 3 until I was home. As noted, the Libre 3 CGM product was just formally introduced to the U.S. market during the preceding quarter (Q3 2022).

Using the Libre 3 was actually a straightforward matter. In fact, it was easy.

Still, I relied upon the official English-language YouTube video tutorials (from the UK and Ireland; note that the readings in the videos are expressed as mmol/L used in Europe rather than in mg/dL used in the U.S.), see FreeStyle Libre 3 - How to Apply the FreeStyle Libre 3 Sensor https://youtu.be/SIu5X52kBAI to watch.

Note that the video will automatically lead into the second video in the series, and the third, and the fourth, etc.). It was actually helpful to watch all of them, and it assisted me in configuring everything to be generally comparable to what I had set-up with Dexcom G6. The Libre 3 insertion device is considerably smaller than the Dexcom G5 device, which was impressive.

For reference, links to the YouTube video library which I relied on for Freestyle Libre 3 were:

FreeStyle Libre 3 - How to Apply the FreeStyle Libre 3 Sensor
https://youtu.be/SIu5X52kBAI

How to Set Up the FreeStyle Libre 3 App & Start the Sensor
https://youtu.be/wUL5r9sDnDs

How to View Your Blood Glucose on the FreeStyle Libre 3 App
https://youtu.be/RescynltW3Y

How to Set Up Glucose Alarms | FreeStyle Libre 3 App
https://youtu.be/DCgIIhcH0-8

How to Share Data to the LibreLinkUp App | FreeStyle Libre 3 App
https://youtu.be/u0wSeruA8A0

I was really impressed that the Libre 3 sensor it is SIGNIFICANTLY smaller than the Dexcom G6; it is really TINY (about the size of a dime, but slightly thicker). I opted to put the Libre 3 sensor on my arm since the most accurate readings for Libre seem to be for arm-worn sensors. That was very easy to do; I simply unscrewed the base (the video warns users NOT to screw the base back on; as it will ruin the sensor), removed the base, held the sensor against my prepped (pre-cleaned with alcohol and dried thoroughly) arm, and pressed down and voila: the Libre 3 sensor was attached. (Incidentally, a very similar insertion device is apparently what the soon-to-be-released Dexcom G7 will feature; no more of the big sensor insertion gun devices!). My main concern is the adhesive around the sensor itself is not very big, and I have already bumped it into a doorway so I worry a little about the 14-day durability of the sensor adhesive. We shall see on that. 

For the newly-inserted Freestyle Libre 3 sensor, in order to activate it, you then need to hold your smartphone against to the sensor until the Libre 3 app chimes (the app has to be open for that to happen), and then the warmup countdown officially begins. That part took me a few attempts since it did not chime on my first try, so I had to try it a second time, and then that worked. Still, it was a fairly easy process. By comparison, to activate the Dexcom G6, I had been scanning the barcode on the sensor adhesive which seemed to work more reliably than entering the numeric codes, but the Libre 3 is even easier: just scan the sensor against your phone and that's the last time you'll ever need to scan the Libre 3 CGM sensor to get a BG reading.

Freestyle Libre 3 has a 1-hour warmup countdown (compared to 2 hours for Dexcom G6, while the not-yet-FDA-approved Dexcom G7 will be ready in just 30 minutes). Being used to a lengthy 2-hour CGM countdown, I could live with the wait; after all, it was still half the time I was used to waiting. Side note: while the countdown time of 1-hour falls in-between Dexcom G6 at 2-hours and the yet-to-be-FDA-approved Dexcom G7 model at just 30-minutes, the Freestyle Libre 3 CGM sensors are approved for a 14-day wear-time compared to only 10 days for Dexcom (G6 or G7). That means each Libre 3 sensor lasts 4-days longer than each Dexcom sensor, thereby saving patients money because they get more wear out of each sensor. Two Libre 3 sensors will last patients 28 days, compared to less than two full weeks with two Dexcom sensors. That, combined with a price that is 30% less, and Libre 3 could save patients a good amount of out-of-pocket dollars. That is a pretty big deal!

In order to use Freestyle Libre 3, I also had to download (and pre-install) Abbott's Freestyle Libre 3 software on my iPhone. 

 

 

Libre 3 does not currently have a stand-alone reader, so an Apple smartphone (or presumably, an Android phone) is a necessity (although it may be theoretically possible with an Apple iPod). I also had to register with LibreView which is Abbott's cloud-based platform (very similar to Dexcom's Clarity platform) enabling data-sharing with loved ones or your doctor, and use the same LibreView login info. on my iPhone app.  During my trial, I told my endo I was trialing Libre, and I needed the "Practice ID", which the office medical techs gave me. Then, I discussed the trial with my doctor, and the staff printed the records for both my Dexcom, as well as my Libre 3. Her observation was how remarkably similar and close the graphs for both Dexcom and Libre 3 appeared to her. She said she really could not discern any difference between them. Based on that, her perspective was that either CGM appears comparable, and she said she was interested in hearing more about my experience with Libre 3 trial during my next visit.

My follower also had to participate in my trial by downloading the LibreLinkUp app to their smartphone. To facilitate following my Libre 3 data, I had to go into the Libre 3 app on my phone, and open the "Connected Apps" submenu within it. I then had to enable my follower(s) "LibreLinkUp" and from there, you select "Add Connection" and you then add the person's name and email address. They'll receive an email invitation to download the LibreLinkUp app and they'll be instantly connected to my readings since I invited them. I don't know with certainty, but it appears the LibreLinkUp app is written by a third-party, so theoretically, your followers could potentially be Android users; I'm not certain about that.

While I was disappointed that Libre 3 does not currently have an Apple Watch complication to view my Libre 3 readings on my watch as I can with Dexcom, I did discover something interesting. You CAN be notified via your Apple Watch for Libre 3 low blood sugar readings. To do so, I had to add myself as a follower and install the LibreLinkUp app to my phone as well. You will receive brief low notifications on your Apple Watch if you do that, although there still isn't a complication to regularly view your Libre 3 BG readings for your Apple Watch. Still, it was a helpful notification, especially if you aren't glued to your iPhone all day.

I kind of hoped to try both Libre 3 and Dexcom G6 concurrently to test their relative accuracy compared to one another, but a single Bluetooth connection on a smartphone essentially forced me to choose either one or the other. Considering I had travel plans abroad in early November, I waited to use Libre 3 until after that happened. The last thing I wanted was to be in Iceland and run out of supplies and not have my CGM with me! 

For me, the old Libre 2's lack of automated alarms and data sharing was perhaps the main reason I stuck with Dexcom's CGM devices as long as I did, while Libre pretty much dominates the CGM market in the rest of the world (Canada is adjacent to the U.S., hence it also has a lot of Dexcom users). People with impaired hypoglycemia awareness were among the earliest adopters of Dexcom CGM's, and they were also among the product's biggest evangelists for obvious reasons. That positive word-of-mouth really helped Dexcom transform itself from a tiny med-tech startup to become a global medical device giant. But over time, the market was presumed by Dexcom to be a certainty (without any perceived risk of losing business to a competitor).

But for me, my Libre 3 trial suggests it may indeed be time for me to consider a more permanent switch to Libre 3. I really wanted to try the yet-to-be-FDA-approved Dexcom G7 to make an informed decision. Below, I acknowledge some of the reasons you might actually wish to consider switching from Dexcom to Abbott Libre 3.

Consider the following reasons:

#1): Abbott Is a Significantly Bigger CGM-Manufacturer Than Dexcom

Abbott is the worldwide market leader for CGM's (Abbott is significantly bigger than rival Dexcom in virtually every country other than the U.S.), with a user-base that was disclosed as "approximately 4.5 million" people globally as of Q3 2022. Abbott's success in the CGM market was driven by its decision to enter Europe before the U.S., where its strategy is a mass-market approach with a lower cost-point than rival CGM systems when cost may be considered as the main driver. That's especially true in Europe where government healthcare systems tend to dominate (some countries like the Netherlands and Switzerland actually rely on private healthcare insurance, but those insurance companies are much more regulated than they are in the U.S.).

#2): Abbott Freestyle Libre 3 Is Less Costly Than Rivals

Beyond global market share, today, in the U.S., the cost differential between the Abbott Freestyle Libre system and rival CGM's is that Libre 3 is priced approximately 30% less (or, as Abbott prefers to say, its rival's CGM's sell for 70% more). That's a very big deal for many payers, and it directly impacts patient out-of-pocket expenses.

As previously noted, Abbott Freestyle Libre 3 is also the longest-wearing patient-installed CGM on the market, with 14-day wear on the upper-arm compared to only 10-days with Dexcom's G6 (and the G7 model, when that eventually receives FDA approval). The longer wear-time adds to the cost-benefit Libre 3 has over Dexcom. Getting four extra days of usage per sensor, combined with a lower price-point spells major cost savings for payers, which includes nearly half of all insured people with high-deductible insurance plans who may pay completely out-of-pocket until they satisfy their deductibles. Both Abbott and Dexcom have worked to secure more widespread CGM coverage regardless of deductibles, but it's a massive job and not everyone's health plan provides that benefit yet.

#3): Freestyle Libre 3 Is MORE Accurate Than Libre 2, Dexcom G6 and G7. Sort of.

First, understand that Continuous Glucose Monitoring ("CGM") systems don't actually measure blood glucose at all, they measure correlated values taken from the interstitial fluid within tissue, while blood glucose measurements are taken directly from the blood. Hence, all CGM's remain an imperfect measure of blood glucose.

The accuracy of CGM's is expressed in a measure known as Mean Absolute Relative Difference ("MARD"), which is a measure of how far the CGM readings are from actual plasma blood glucose levels; a percentage of zero means there would be no difference from actual blood glucose, hence the lower the percentage MARD is, the more accurate the reading is. Said another way, the closer to zero the MARD is, the MORE accurate the CGM reading is because a MARD percentage of zero would mean there is NO difference between the CGM and plasma blood glucose level.

Freestyle Libre 3 is MORE accurate than both the old Libre 2, the Dexcom G6 or the yet-to-be-FDA-approved G7. Well, sort of. I'll elaborate on that in the next paragraph. The MARD percentage for the older Abbott Freestyle Libre 2 model was 9.2% compared to just 7.9% on the newer Abbott Freestyle Libre 3 model.

By comparison, the MARD percentage for Dexcom's G6 model (the current Dexcom model) is 9.0% while the MARD percentage on the yet-to-be-launched (or FDA-approved) new Dexcom G7 model is 8.1% for arm-placed sensors and 9.3% for abdomen-placed sensors.

#3b): What I Mean When I say Libre 3's MARD is 7.9%…"Sort of"

When I said the Libre 3 MARD was "sort of" 7.9%, what I meant by that is the Abbott's Freestyle Libre 3 MARD percentage varied over the CGM's 14-day period of usage, which means that its accuracy varied over time. Regulatory data submitted to the European regulators showed the MARD percentages were acknowledged to be slightly greater in variance from plasma blood glucose (11.2% MARD on day 1), while it improves slightly on days 2-6, improving further to 8.5% on days 7-12 (its MOST ACCURATE days), while the MARD percentage on days 13-14 increased slightly to 9.2%, which is about what Dexcom G6 is today. (Nerdabetic covered MARD a bit at https://youtu.be/IQVxZz0S2_A if you're interested in hearing his perspective on the subject.)

The Libre 3's overall MARD percentage was 7.9%, but that is its AVERAGE over 14-days of usage, so keep that in mind. (Perhaps we need both mean and median MARD figures?) Incidentally, I found nearly identical issues with Dexcom G6 as the first and last few days of wear tended to give more erratic numbers which differed more widely from fingerstick readings. However, unlike Dexcom, Abbott Freestyle Libre 3 does NOT offer patients the ability to calibrate their readings; you are expected to simply accept Libre's readings without trying to correct them which, if I am being honest, really bothered me. That was the one thing I really hated about Libre 3.

That said, Dexcom's most recent non-optional software update really altered how it handles calibrations compared to how the previous iteration of its software dealt with calibrations. It now tends to simply disregard patient calibrations compared to previous versions of the software, raising the question: why bother? Dexcom's conscious decision to pay less attention to patient calibrations is a pain-in-the-ass which I really dislike but I also disliked that about Freestyle Libre 3. In my mind, it means there is now practically no difference between Dexcom and Abbott Libre 3 in my opinion on my ability to keep the readings on-track. Given that, it also made me really question whether Dexcom really has ANY genuine advantage over Libre anymore? In my mind, they both are essentially saying "trust us", but I know better than to trust either of them given the scientific reality that neither Libre nor Dexcom actually measures blood glucose but correlations in interstitial fluid. Neither is perfect.

Abbott has released some conflicting data on the MARD percentages for the new Freestyle Libre 3 at several different times over the past year. Analysts questioned company executives about those differences, and the explanation given by Abbott was a bit vague and not completely persuasive, attributing the differences in calculations used by European regulators and U.S. FDA regulators, which seemed questionable. It's possible the executive answering the question simply did not have the facts handy when they were questioned, or it could have been an error in a report which the company hoped no one would notice. However, we kind of have to take the company's word that "FreeStyle Libre 3 has an overall mean absolute relative difference (MARD) of 7.9%" over 14-days of usage since that was the MARD percentage the company is reporting, and Abbott has used that MARD figure ever since.

What We Actually KNOW About MARD Percentages

It's very certain that the newer model CGM's from both Abbott and Dexcom are improvements over their older CGM models, and its perhaps best stated this way: I think we can only say that the Freestyle Libre 3 and Dexcom G7 had marginal differences in MARD percentages between the two CGM brands. In other words, Libre is more accurate, albeit by a very miniscule percentage and it really depends upon which day since you inserted your Libre 3 sensor that you're on. But I believe the same is true for Dexcom MARD variances, only I do not KNOW those figures. But I have definitely seen it in comparisons to fingerstick readings (which I ALWAYS trust more than CGM readings), so I'm certain the same MARD curve of accuracy applies to Dexcom.

That said, as noted. because CGM's rely on interstitial fluid correlated readings, they are all imperfect. I found Libre 3 often showed significantly higher BG levels than fingerstick readings after eating on the first few days (often giving me alarms for high blood sugar readings), so I simply adjusted my high alarms on Libre 3 even higher so the alarms did not bother me unnecessarily for something I already had insulin on-board to treat. That adjustment to Libre 3's high alarms worked very well for me. In my nearly half-century of living with T1D, I rarely miss dosages of insulin as some newly-diagnosed patients do, so I really do not really need high alarms at all. That's not my problem area. Fortunately, the next Libre 3 benefit kind of offsets that.

#4): Freestyle Libre 3 Updates Readings Every Minute; Dexcom Only Updates Every 5 Minutes

A critically-important Libre 3 advantage has over the existing Dexcom G6 as well as the yet-to-be-FDA-approved Dexcom G7 is that Freestyle Libre 3 sends updates to your phone EVERY MINUTE, whereas both Dexcom models only send updates every five minutes, which can save patients from irritating repeat alarms. That's a feature I really, REALLY like, and it's a definite advantage Libre 3 has over any model of Dexcom. Dexcom can be annoying at how infrequently readings are actually updated and so that's a big plus for Libre 3.

#5): Freestyle Libre 3 Can Be Worn for 4-Days Longer Than Dexcom, Saving Patients Money

The Abbott Freestyle Libre 3 says it features unsurpassed 14-day accuracy, while the new Dexcom G7 sensor is indicated to be worn for a maximum of 10 days (plus a 12-hour grace period). In other words, not only are Dexcom G6/G7 more expensive than Freestyle Libre 3, but you also get 4 fewer days of wear out of each more-expensive Dexcom sensor (described another way, patients actually get nearly a full month out of just two Freestyle Libre 3 sensors (28 days with just two Freestyle Libre 3 sensors, meaning the entire month of February), while a Dexcom system requires three sensors for 30 days. Simply put, when you can wear a CGM sensor like Libre 3 for longer, your cost of replacing sensors means spending less money out of your pocket.

Breakdown of Key Advantages and Disadvantages for Libre 3, Unapproved Dexcom G7

The Abbott Freestyle Libre 3 does have a few slight DISADVANTAGES to Dexcom on two very specific matters, specifically: Dexcom G7 wins on slightly-faster warmup time, and on compatibility with several AID systems.

The yet-to-be-FDA-approved Dexcom G7 warmup time will be just 30 minutes, while the warm-up time for the new Freestyle Libre 3 is one hour. Neither is as long as the 2 hours patients now endure with Dexcom G6, so patients would not have to wait as long with either of the new CGM's.

But the half-hour difference in warmup time doesn't really give patients any material extra usage from each sensor because Dexcom forces you change its sensors every 10 days compared to Libre 3's 14-day wear-time. In my view, that means in terms of Dexcom advantage is not as terrific as it seems. Also, since I've been using Dexcom G6, so I'm already used to waiting 2 hours for readings while the new sensors warm-up. Sure, shorter is better, but a half-hour isn't a deal-breaker in my opinion if it means paying much more out-of-pocket.

For some patients, Dexcom also retains a slight advantage over Freestyle Libre 3 on AID (Automated Insulin Delivery) systems because of the number of deals Dexcom has already signed with pump and smart-pen companies operating in the U.S. I do not necessarily envision those will be long-term threats to Abbott because its CGM sells for 30% less money, and as the saying goes: money talks and bull$#!t walks. Abbott's cost differential means it is conceivable that Abbott could persuade enough insurance company payers to start "preferring" Libre 3 over Dexcom G7. 

We shall see on whether Abbott tries it. In the past, some medical device companies tried to seal a "preferred" placement for insulin pumps with United Healthcare, and it blew up in Medtronic's and United Healthcare's faces. People absolutely hated being told which device they had to use if insurance paid for it, and that preference later ended with a whimper. It's one matter to do it on insulin or test strips, but with a device which patients have physically attached to their bodies, that was a rather different concept.

For the time being, I am really enjoying Libre 3. And, I may opt to continue it permanently in 2023 depending out my out-of-pocket costs for Dexcom when the deductible resets.

 

 

#6: Freestyle Libre 3 is Tiny

Like really tiny. 

Even I was impressed at how small it was. It's like the size of a dime, only a little thicker (I bruised my arm with the first sensor installation, but I wanted to ensure it stuck because of how small it was!). There isn't much adhesive surrounding each sensor, hence over-patches may not be feasible (although standard medical tape would work). 

Enjoying the Silence!

But more importantly, the Libre 3 alarms seem to be far less needy and demanding for me, which is actually really good. Dexcom updates its readings every five minutes, which means recoveries from hypos can take a good 20-30 minutes for the recoveries to even show up on my Dexcom G6, and sometimes the damn thing repeats its annoying alarms after 15 minutes even after I have treated the hypo already which is incredibly annoying. After 46 years of living with T1D, I don't want diabetes to interrupt me constantly as it too often does with Dexcom G6. I also don't know if Dexcom G7 will prove less needy and demanding with alarms than the Dexcom G6 does. I certainly hope so.

Libre 3 has given me some much-needed alarm silence which is priceless!

Beyond that, I may be ready to give Libre 3 a more permanent try and save myself cash in the process. However, I really want to try the new Dexcom G7 to truly compare the features/benefits of the new CGM's to get an informed perspective. That said, insurance deductibles reset to zero on January 1, 2022, so enjoying lower out-of-pocket costs could be very persuasive while satisfying deductibles. Watch this space!