By Tavia Vital BSN, BA, RN, CDCES
To better understand the real-world experience of using the new Libre2 app, I tried it out.
I normally wear a Dexcom sensor so, I decided to wear both at the same time. In order to share my adventure with you, I took a few notes and a few pictures along the way!
Wearing another device along with my normal pump site and Dexcom sensor was an interesting experience. It was one more spot to pay attention to in order to avoid smushing it or smacking it on something. The insertion was uneventful, as expected. The app install and start up process was very simple. The app walked me through all the important steps, including safety information.
Just like we know that our fingerstick glucose readings will not match our sensor readings, it is expected that the two sensors will read differently from one another.
Sometimes they did read very similarly:
Sometimes, however, my experience was more along the lines of watching an ongoing family fight.
I, also, thought about two children arguing over who broke a toy, or who is right and who is wrong.
Freestyle Libre2: “I’m the best.I’m right!Pay attention to me!!”
Dexcom G6: “No, I’m the best!I’m right!Listen to me!!”
The variability did provide interesting fodder for some funny text messages between myself and the IDS Team!
Along the way I noticed the Freestyle Libre 2 seemed to do a high number of ‘post reading auto-adjusting’.
What I mean by this is: I get an alert. I scan to see my reading. It reads a false low, such as 54 or 68 mg/dL when I am actually in target according to a finger stick and the Dexcom. A few minutes later, I scan again and the new reading is something much higher, such as 131 or 125 mg/dL AND the previous false low reading is missing from the graph. It is as if the device realized it was wrong and then smoothed it over on the display graph. Although you can get updated glucose info every minute with the Libre2 app, which can allow you to identify a rapidly dropping glucose more quickly than Dexcom sometimes does, overall, I found this to feel a bit unsettling to me.
I like the Dexcom G6 mobile app normal display graph compared to Freestyle Libre2 app.
With Dexcom, the default graph display is a 3-hour graph. The 3-hour graph provides enough info to see where I’ve been, where I’m at, and how fast my glucose is moving now. I don’t need to see what my glucose was at 2 p.m. to decide if I need to take correction insulin before bed today. If I want to see a 24-hour graph, I can rotate my cell phone to the side.
With the Libre2 app, you get a full 24-hour graph at all times, except briefly after scanning to see your current glucose and rate of change + direction info.
The 24-hour graph is displayed across the normal cell phone screen without rotating it to the side. This causes the graph to be squished together. This squished look makes it look like there is a greater amount of variability over the past 24 hours compared to how it appears sprawled across the landscape view of the Dexcom app.
When comparing the AGP (Average Glucose Profile) reports between the two devices, LibreView reports showed a lower average, GMI, and increased Time in Range compared to Dexcom Clarity reports. Of note, the Libre 2 report averages are closer to my usual A1C than what the Dexcom shows.
There were a few other things I did not find helpful with the Libre2 app:
- I received a very high number of false low alerts. I did place the sensor on the back of my arm, per the package instructions. Every time I laid on my back to sleep, the alert would go off indicating I needed to scan due to hypoglycemia. This caused item number 2 to occur.
- I did not sleep as well as usual due to frequent false hypoglycemia alerts.
- Since I am used to living with the Dexcom, I did not enjoy the extra steps of pushing a button, waving my phone by my arm in precisely the right spot to elicit a scan to be able to view my reading.
As we all know, there can be variability from site to site and sensor to sensor. This means I can’t just say the Libre 2 is less accurate than the Dexcom G6 for me. In order to make such a bold statement, I would need to wear a Libre 2 sensor a few more sensors before I would want to fully discuss my experience with accuracy. Since each person with diabetes is a unique individual, what works well for me may not work as well for another person. What doesn’t work well for me may work amazingly well for another person with diabetes.
All in all, it was a good learning experience for me. I am glad I tried out the new Freestyle Libre 2 app. The alerts that prompted me to scan when a glucose may be out of target is an important safety feature that I would, personally, require for my diabetes self-management. I do not always have symptoms when I am above or below target, so I do rely on my Dexcom to keep me informed when I may need to take action to prevent or treat a low, or to take a correction dose for an above target glucose level. The app allows for detailed, yet efficient, note taking which is helpful when reviewing data.
For more information about the Libre 2, see:
What has your experience been using the new Libre 2 app?
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False lows happen at least 2-3 times a week in the middle if the night. It us so frustrating
using an alternate site to avoid compression when sleeping helps. I have also seen patients have good reduction in compression lows from all CGMs by using egg crate style pads on their beds.