After six years of MDI, I finally dragged myself screaming and kicking to CGM technology, convenience and expense. For reasons beyond the scope of this post, I began by using the Dexcom G4 for a total of two months before my endo ordered a G5. Some might see the G5 as an upgrade; I beg to differ.
The G4 never dropped data, registered a difference of more than ten percent, or crapped out for five minutes or two hours – but these are persistent issues with the G5. I read other posts suggesting corrections such as (i) changing sleeping positions, (ii) carrying the receiver within eight inches of the sensor site, (iii) being out of range entirely, (iv) first-day-or-two jitters while the sensor gets its act together, and (v) receiver not communicating with Share. These issues never had to be addressed with the G4.
The G5 regularly loses the signal for anywhere between 15 minutes to two hours; registers readings either double or half of a fingerstick; asks for calibration ten minutes after one is already entered; has registered one reading 10 or 20 points higher or lower than the one immediately previous. Furthering the frustration is that no pattern can be detected whether night-time, post-meal, post-bolus, or moon phase.
So the question is, in light of the issues and inaccuracies [read: unreliability] of the G5, why bother at all with CGM? I can think of plenty of uses for the same money, although they might not offer as many surprises.
If you have encountered similar frustrations, please share how or whether you got around them.
I still use the G4, because I have the Animas Vibe and the G5 doesn’t integrate with it. I have occasionally have some of the issues you describe (had a1.5-hour interruption on Friday night), but they have been the exception, not the rule. The vast majority of the time, I have had consistent readings and have been quite happy with the CGM’s benefits.
I would call Dexcom and complain – and keep on calling and complaining about the issues until they either resolve them. There are folks that have had good results with the G5. For now, though, I’m staying with G4…
I’ve used both the G4 and G5 and found that there are pro’s and con’s to both depending on what is important to you.
G4 definitely seemed to have a more reliable connection and better range. Possible (but a pain) to setup a cloud system.
G5 allows me to easily use apple/android smartwatches to monitor using the cloud. Less devices since you can use an iPhone independently. It automatically updates to Dexcom Clarity. Because I can use Nightwatch, I am able to use multiple “smart” alerts for total customization of sounds and snoozes. I definitely get more “blackouts” with G5. The G5 is slightly thicker than the G4, which doesn’t sound like a big deal–but I notice pressure lows more often because it is pressing against things more often.
All-in-all. I love the G4 and G5. Definite improvements to be made–but good product overall.
I’m sorry to hear you have had these issues. Our experience has not been the same. We very much appreciate the improvements of G5 and don’t see a change in lost connection or accuracy. Range may be shorter, but my son has his phone with him much more than his receiver, so it hasn’t caused us any frustration.
I do agree that making these experiences known to Dexcom can be helpful. The more they receive the message of this experience, the more power it will have to influence change.
You have to realize that the G5 transmitter is more susceptible to interference as it transmits a Bluetooth signal rather than the G4 transmitter which transmits a basic RF signal.
It’s my understanding that the G4 system has four very specific frequencies while the G5 system has a range of frequencies (2.402-2.480ghz). Now, I’m not going to try to act smarter than I am, but it’s my understanding that it’s interference from other Bluetooth devices that generally causes the issue rather than the transmitter itself. In theory, removing interference should prevent the signal loss issues some are experiencing.
Furthermore, I’ve read that the software in the G5 system is different from that of the G4. I’ve learned to only input BG meter calibration values when it asks for them, and if I input a value when there is a great deal of fluctuation in my levels it seems more likely that it will ask for another value much sooner.
Even though I’ve been able to keep issues with my G5 to a minimum, I will admit that it’s obviously not perfect. With that said, there is most definitely still a point to having it and I’ve been extremely impressed with the accuracy of mine.
That matches what I understand about how Bluetooth works as well. I have a G5, and I use both the iPhone app and my G4 receiver (updated to work with the G5 transmitter). I find that the iPhone app has a lot more—and more prolonged—dropouts, whereas with the receiver I see only a few and usually only for a sample or two (5 or 10 minutes), pretty much unchanged from before the upgrade. As far as app dropouts go, they are particularly prone to occur overnight, sometimes for like an hour (with my phone sitting right next to me on my bedside table, right next to the receiver). I’ve unpaired a lot of unnecessary BT connections on my phone, which I’ve heard can help, but the discrepancy is still evident.
This is the most reasonable explanation thus far, thank you for sharing it! Although my use of Bluetooth is zero, nor do I own i-anything, I am surrounded by those who do. (At least one suggestion I may offer Dexcom is a feature to disable the Bluetooth.)
On first read, your explanation does not seem plausible as a cause for night-time dropouts. BUT the more I ponder signal interference, the more sense it makes. Signal interference probably travels on consistent, uninterrupted continuum at night because device movement is minimized. During the day, though, devices are in constant motion – so no stationary signal “barrier” builds up.
Raises a new question for G5 users: If you experience prolonged dropouts overnight, are you in densely populated urban areas? Users who do not experience data drops and enjoy greater then 60% accuracy, are you in areas considered more suburban? Is there anyone else out there who does not use the Bluetooth feature?
@Muragaki That is a very interesting idea. I live in a fairly rural area. I receive dropouts maybe once a week (although it seems to come in clusters). I have heard that baby monitors can interfere–and not to keep the apple device too close to the receiver, but I hadn’t thought about other Bluetooth devices. I have a smartwatch–so maybe that is something to think about. Thanks!
My experience and opinion has been much as yours. I wanted to return to a G4 (share) but Dexcom says they are no longer available. All I had was the pre-share G4 receiver. The range of a G5 is pathetic. The battery life on the transmitter is a bad and expensive joke.
As you, I find them LESS accurate than my old G4 yet Dexcom was able to get FDA approval for dosing.
Just to top it off, the android app which was continually promised in December 2015 and most of spring 2016 still isn’t here. I suspect the Bluetooth decision was made so the transmitters could connect to Apples. Too bad I am an Android user. Catering to Apple users (a minority) instead of Android users (a majority) makes sense as a proof of concept but has really riled this long-term user because of their infamous “Android shortly” pronouncements.
Interesting. We’ve never gotten less than a year out of a G4 transmitter. My daughter just changed to a new one a few days ago. It was 14 1/2 months old.
I have found my G5 to be more accurate overall with the one exception being the first 24 hours or so. It is WILDLY inaccurate for the first 8 hours, most of the time dropping all the way to “Urgent Low” and staying there until I calibrate again, and even sometimes going back after calibrating. That or it will read extremely high and I will actually be about 50 - 100 mg lower than that. It is very annoying I can’t rely on it that first night as that is when i need it the most (due to not waking from lows).
One trick that you can do is to insert the new sensor while the old one is still working. In order to protect this new sensor, insert an old expired transmitter on which you have written “old” or out a large “X” on top so you never get it confused with an operational transmitter. Wait at least 12 hours to stop the previous operational sensor. At this point remove the dummy transmitter from the new sensor and insert the operational transmitter. Start the sensor session as usual.
This was a trick that I used back in my days of using Medtronic SofSensors. This process allows the sensor to “wet” and become accustomed to your body. It should then be more accurate when you finally start it.
The downsides of using this procedure are that you 1) must plan ahead of time when you are going to replace your sensor and 2) must be very comfortable replacing transmitters in a sensor and 3) must have an old expired transmitter. It is possible that you could do something else to protect the new sensor when it is inserted early, but a transmitter gives the best protection.
While I would definitely be open to trying that, my main problem is lack of real estate. I absolutely have to use a large transparent dressing over my CGM, and a smaller one over my infusion set, to keep them in place which doesn’t give much room to put another one. I might be able to make it work though, so I will see about that. I certainly have no issue removing the transmitter, and I have at least one old one laying around.
Very similar to my experience. I got the G5 as soon as it was available and went from having a never-dropped signal with the G4, to frequent, erratic drop outs on the G5. I live in a very rural area and this would happen while hiking, so competition from other Bluetooth devices for connection didn’t really explain the source of the problem. In the end I went back to the G4. Its a shame, as I couldn’t wait to get hold of the G5. My worry is that Dexcom may have prioritised getting something with better features out, but overlooked that stability is essential – and no feature can be at the expense of that basic requirement.
I just bought a really nice set of Bluetooth headphones. If I upgrade from the G4 to the G5 will I be able to listen to my BG levels as well as my music ?
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