Some Info on Dexcom 7 accuracy

I had an offer from Dexcom to get a free G7 receiver. But it would have required switching from G6 to G7. So I called Dexcom tech support and asked about the problem many users talk about: spiky readings which give false out of range alarms, and sometimes miss real out of range situations. (MARDI does not capture this. MARDI is a median, which does not really capture extremes.) I talked to Stephanie, a very nice person at tech support who told me that Dexcom was aware of the problem, working on it, but (as far as she knew, not being in research) they still did not know exactly why that was happening. So I’m going to hold off switching to the G7 in hopes that Dexcom will diagnose and solve the problem before the upgrade becomes mandatory. Not everyone runs into this with the G7, but if I can I’ll avoid the gamble, and wait unitl it is fixed. At any rate, if you are thinking of upgrading from the G6 to G7, you might want to take that into consideration.


The G6 was smoothing out the variations and showing sometimes inaccurate reading to make the char lines smooth. With the G7 it is displaying more accurate single reading points w/o the smoothing of the chart lines. This is how it was designed so the connected devices do the averaging in the various algorithms, and not have the real-time Dex readings and causing inaccurate estimates to adjust dosing and trends. It’s not a problem to solve, but rather more accurate real-time data for the algorithms.


I agree with Sjwprod here. For both the G6 and G7 the measurements can jump around when the sensor is detecting inconsistent readings, typically early in the life of a new sensor, and late in the sensor life when it is starting to fail. The G6 hides those jumps to pretend everything’s just fine, whereas the G7 reveals the jumpiness, which actually is valuable information to an algorithm, because it is an indication that the CGM readings are less reliable, so more care needs to be taken to avoid an accidental hypo.


Thank you for your honest evaluation of the Dexcom G6 verses G7. I will be waiting until the quirks have attention.

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There are a lot of users reporting problems with the G7, but the people that aren’t seeing those problems don’t complain as much and you don’t hear about the happy switchers. I’m here to offset that. I switched to the G7 months ago and it has been better than the G6 in every way. Stays on better, smaller, more comfortable, starts up faster, doesn’t have crazy readings on the first day, and has been much more accurate for me. The G6 would occasionally give me badly erroneous readings (50-100 high or low) that would have caused me huge problems if I believed them, but I’ve never had a reading that inaccurate on the G7. It also costs me half as much in insurance copays because I’m only paying one copay for the sensors instead of one for the sensors and another for the transmitter like on the G6. I ignored the many reported quirks and gave it a try for myself and was glad I did. You might consider giving it a shot too before all of the loud people online say you should.


Replying to the replies. First, the problems are NOT just during the first 24 hours. 2nd, BWschulz, I should have emphasized that it is a small percentage of users; most do not run into tis. But third; it is a real problem Dexcom acknowledges it as a problem. Again, I talked to a Dexcom tech. It is a problem they are aware of , and are trying to find the cause of. It is not a question of “loudness.” Of course people who run into problems after expecting an improvement wil complain loudly. But anyone who ran into this would complain. Again,for most the G7 works better than the G6 and better than the Libre 3 as well. :But my particular insurance, if I switched would put major obstacles in switching back. That is why I am waing as long asd possible to switch in hopes they will diagnose the problem before I make the move, so that I don’t run into the problem of switching to something that does not work and then having a major fight on my hands to switch back. Dexcom is one of the best CGM companies in terms of technical prowress out there. I believe they will ultimately figure out what is going on. But apparently it is tricky diagnosing this problem - which again at least the tech I talked to acknowledges as real.

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Very understandable to delay switching if insurance makes it difficult- in my situation I had 2 prescriptions and could just have refilled the G6 instead of the G7 if I wanted to. That’s a huge difference. YMMV a lot depending on insurance coverage/approvals.
I’ve just seen lots of complaints online that I have never observed myself and would just like to put my counterpoint experience out there. Other benefits I forgot to mention are that I don’t need SkinTac to get the G7 to stay on (which is good, because I’m not sure how I could use it!), I don’t need to buy separate overpatches anymore to keep it on, and the 12h grace period is also awesome. My only sort-of complaint is that I can’t restart the sensors anymore to double my days per sensor, but the 1/2 price reduction due to one copay offsets this.

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Our son had switched to the G7 a few months ago, and he liked it for the same reasons bwschulz mentioned. We found it accurate enough, as good as the G6 or better. The only slight downside we found was the Bluetooth distance, or lack thereof. He had to have his phone closer than with the G6. Not a big deal at all. Overall great experience. We had to switch back to the G6 though, so that he can now use the G6/Omnipod 5 combo, which is quite awesome.