One thing I’ve noticed with the G6 that I never noticed with the G4 or G5 is that it can provide results that are inconsistent with themselves. For example, I might get 120 with a full down arrow (ie at 120 and dropping fast) and then, when it does the 5 minute refresh, the next result is 128 with a diagonal down arrow (ie at 128 and dropping at a moderate rate). How can my BG rise from 120 to 128 from one reading to the next and yet still be dropping? I see internally inconsistent 5-minute jumps like this I would guess about once a day if not more often.
I would not say that the G6 is necessarily less accurate the the two previous Dexcoms. I find them all pretty good. My sense, though, is that the G4 and G5 kept their story straight whereas the G6 is more volatile.
This shows up in ways that are not, strictly speaking, inconsistent, but that strike me as a little implausible, too. For example, I’ve seen a BG of 220 with double rising arrows, refreshed it 5 minutes later, and seen 218 with a flat arrow. It’s certainly possible that my BG rose rapidly and then leveled off just as rapidly, but it’s not something I ever remember seeing on the previous incarnations of the Dexcom. If my blood sugar was rising rapidly it would take a while to level off.
Has anyone else had this experience? Is there something about the new algorithm that allows it to jump around more?
On the subject of calibrations, I’ve noticed that if it’s off (usually reading consistently lower than my meter) and I calibrate it, it will almost invariably within an hour or so, start being off in the other direction (reading consistently higher than my meter.) It makes me wonder whether calibrating is wise. My experience with calibrating the G4 and G5 was that it was best not to over calibrate, but that occasional calibrations could bring it closer to fingerstick readings without tipping it into going the other way.
These issues are far from dealbreakers for me, but they do leave me puzzled.