WRITTEN BY: Lea Raak and James Mansfield
Editor’s Note: James Mansfield is a member of Beyond Type 1’s leadership council, and recently had the opportunity to try out the Eversense CGM. Lea Raak, founder of the blog Insulea, simultaneously tried the Eversense XL continuous glucose monitor (CGM) system in Germany. The views and opinions expressed in this article are solely those of the authors and do not necessarily reflect the position of Beyond Type 1.
What is the Eversense?
James: The Eversense is a new CGM that has been available in several European countries since 2016. It recently received FDA approval and the process of launching in the United States is underway. The Eversense system is comprised of a tiny sensor which is implanted just below the skin by a physician and a transmitter which is worn on the outside of the skin. An app on your phone displays your blood sugar readout, but the transmitter on your skin continues to read the sensor and provides on-body vibration alerts even when the phone is out of range. The transmitter can quickly and easily be removed and placed back in position at any time. The sensor insertion/removal requires a procedure by a certified physician. In the US, the Eversense sensor needs to be replaced every three months, whereas in Europe the EversenseXL is available with a sensor that lasts for six months.
Adhesive
James: The adhesive is by far the main differentiator of the Eversense from their competition – this was easily the best thing for me. Because the sensor is fully below the skin, the transmitter adhesive can be changed as often as you like. Each adhesive patch lasts a day and can be peeled off and stuck right back on multiple times per day. Because the adhesive only has to last a day, it is completely hypoallergenic. Technically, you can stick the transmitter on however you like – while at work once, I ruined my Eversense patch and just stuck the transmitter back using materials from an office first aid kit!
Lea: I wanted to test the system because I was curious about having the sensor underneath my skin which officially qualifies me as an actual cyborg. Go me. I always have trouble with the adhesive patches from CGMs or pumps – they keep falling off or peeling off after a few days. I know there is tape but even tape can’t keep up with my skin! So, I was really pleased to learn that I can change the transmitter adhesive every day – this is a huge plus for me!
On-body vibration alerts
James: Another thing that differentiates the Eversense is its on-body vibration alerts. The transmitter will vibrate to alert you to lows, highs, or predicted lows or highs. There’s a different vibration pattern for each, and you do not need your phone with you – this is great for when you’re running, swimming, working out, or during social situations when it’s inconvenient to look at a phone or watch.
Lea: The on-body vibration alerts are quite useful for sports or social activities as James already mentioned. But they can border on annoying, especially when the readings are not right and it’s basically a false alarm. In my opinion, the alarm for low blood glucose is too long. When it’s really quiet, the vibration can be a bit loud and distracting. Sometimes I’m also just not up to explaining my diabetes to other people, so I want my tech stuff to be quiet and hidden.
Fewer supplies
James: You can fit 3 months worth of Eversense supplies in one pocket. Supplies consist of adhesive patches and a USB charging cable. This is great for traveling and for the environmentally conscious among us.
Lea: I love that there is not as much plastic waste with it! Also, it’s very convenient when traveling.
Calibrations + charging
James: The Eversense needs to be calibrated to a finger stick measurement every 10-14 hours. Your calibrations have to be within scheduled calibration time windows (which you can customize). So I need to calibrate between 5:30AM-8:30AM and between 5:30PM-8:30PM each day, my chosen timeframes. These windows added an extra layer of annoyance to having to calibrate. For example, on a long flight I fell asleep, woke up and was no longer getting readings because I had missed the scheduled calibration time. Or at work I have forgotten my blood glucose meter at home and had to just enter a fake reading to stop it from shutting off. The transmitter needs to be charged every 24-36 hours. For me this was not a big deal as I would remove it and charge when I showered each day. It charges fast – only about 15 minutes from no charge to full charge and the cable plugs into USB.
App
James: The Eversense app gives you loads of options — too many, in fact. It is very cluttered and can become confusing. For example you set an “ideal range” as well as an “alert range” which can’t overlap. When I run I like to set my low alerts higher so I can preempt lows, and it took a long time to realize that I couldn’t increase my low alert because my “ideal range” was blocking it. There’s also a “my glucose” screen which is different from the “glucose” screen in settings. One nice thing about the app is that you can swipe to scrub back through your day and see in detail what your trend line looked like earlier (rather than having to just look at a preset 6, 12, or 24 hour screen).There is also a sharing app called “Eversense NOW” which is essentially a replica of the Dexcom “Follow” app, to follow friends or family.
Lea: I love that that the app shows me reports and pie charts of my glucose levels in 48 hours, 7, 14 or 30 days. The time-in-range is a pretty important feature to me!
Insertion procedure
James: The insertion requires a visit to a certified physicians’s office. Since Eversense is new to the US, there are not many certified doctors yet. I had to drive hours away to get mine inserted, and I was one of the three initial patients required for this particular doctor’s certification. Because it was not my regular endocrinologist, it also required more new patient paperwork and waiting around. The procedure itself was totally painless and pretty easy. Even once the lidocaine wore off, there was still no pain, and the wound healed over quickly.
Lea: The insertion was completely painless and didn’t take longer than 10 minutes. The doctor allowed me to take a video of the procedure. Before and afterwards two sales persons helped me setting up the Eversense App and connecting the transmitter with it. All in all it was quite uneventful and even though it looks pretty scary in the video it is not scary at all. So don’t let that fool you!
Scarring
James: Yes this does leave a visible scar. For me I still have a clear scar 1.5 months after the insertion. I spoke to an endocrinologist who has received Eversense training, and she advised me that it is possible to continue to reopen the same incision and place replacement sensors into the exact same spot. In fact she said this is what she would recommend. Personally I have not done this, but if I chose to keep wearing the Eversense long term, this is what I would do to avoid having new scars every 3 months.
Accuracy
James: Eversense commonly quote “MARD” (mean absolute relative difference) values to illustrate the accuracy of their system. The Eversense MARD is advertised as 8.5%, very close to the quoted 9.0% achieved by the Dexcom G6 (lower is better). In real life, my personal experience was that my Dexcom G6 worn simultaneously with the Eversense provided readings which were generally closer to finger sticks, and that individual readings from both systems tended to be pretty close to one another and to each finger stick reading. However, what I found to be a major difference was that the Eversense trend line “bounces” around slightly, while the Dexcom is very smooth. The smooth Dexcom line makes it much easier to intuit what will happen next and to preempt highs and lows. As the Eversense bounces, it’s harder to know if you’re about to go up, down, or stay level. Since I take a proactive management style based on my CGM, this was a critical issue for me. I spoke to Eversense and they advised that they were aware of these and that they were working on improving the “smoothing” algorithm for the trend line.
Lea: As I mentioned before the readings can be quite off. I will give it some more time to level off, but I’ve had the same problem with the Freestyle Libre from Abbott before. My Dexcom is always perfectly accurate compared to my glucose meter. So I am definitely spoiled.
Can the transmitter get wet?
James: I’ve worn it in the ocean, in pools, and in the shower. In fact, the on-body vibration alerts continue to work underwater, which is very handy, especially since you are unlikely to have your cell phone with you during that time. The sensor to transmitter communication is near field, which works underwater, unlike Bluetooth.
Lea: I also like that I can take the Eversense sensor off while I’m taking my morning shower. That’s the perfect time to charge it too and I haven’t have any problems with a low battery yet.
Cost and Insurance
James: Eversense describe the list retail price for their system as comparable to the list retail price for the Dexcom G6. The retail prices they quoted me are as follows:
- a single transmitter which lasts 12 months: $550
- each sensor which lasts 3 months: $850 (so $3,400 for a year)
I ran the doctor’s visit and insertion procedure through my insurance, a Blue Shield of California PPO plan. List price for the insertion procedure (billed by the doctor) was $710.00. “Network savings” reduced the price by $444.22, and Blue Shield paid $221.30. Out of pocket for me therefore came out to $44.48. I ran the Eversense system through my health insurance provider as well. They cover the system under my durable medical equipment benefit. Based on my 50% DME coverage, the Eversense out of pocket cost for me would be $853.55 initially (for a 12 month transmitter and 3 month sensor), and then $463.05 every 3 months for the replacement sensors. Eversense sometimes offers discounts via various programs.
I was originally going to have the insertion done by my regular endocrinologist (a member of BT1’s Science Advisory Council). However, they chose not to move forward with offering the Eversense because there was no proper way for them to bill the insertion procedure through patients’ insurance. So there seems to be a barrier to entry not just on the patient level, but also for endocrinologists wishing to offer the technology.
Conclusion
James: I feel really fortunate, particularly here in the US, to have another CGM product option. I think it’s good to have competition, and T1D care is so individual that it really is beneficial to have different choices. What is important to one person might not be to someone else. If I had to choose between not having a CGM or having an Eversense, I would choose Eversense in a heartbeat. However, for me, the Dexcom G6 with its easy self-insertion, no calibrations, wide availability (including steeply discounted at Costco), clean interface, and smooth, accurate trend line is a no brainer. When I removed the Eversense and put back on the Dexcom, it felt like clouds parted. It was easier to read, with fewer alarms, and less mental noise to worry about (calibrations, charging, body alerts). I could see the Eversense being useful to people who have severe allergy or skin reaction issues with the strong multi-day wear adhesives used by competitors, or who are unable to keep those stuck on. For me, however, the scarring, current lack of availability and coverage, and strongly competitive alternatives mean that when I get the Eversense sensor taken out, I probably won’t be putting a new one in.
Editorial Disclosure: Companies mentioned in this piece, Eversense and Dexcom, are partners of Beyond Type 1. This content was not published as a part of those partnerships, but rather to help share information about CGM technology options for those impacted by T1D.
