Biggest discrepancy between Dexcom and fingerstick ever?

So, Samson had french toast this morning and Loop didn’t bolus him because it said he was very low. (like LOW).

Afterwards, on finger stick? Three separate tests, with hands washed between all: 460. 439. 437.

Anyways, that’s a pretty big discrepancy. I wanted to change it out but Samson has begun dreading sensor changes and begged to wait. So we calibrated and Dexcom just didn’t believe us. Currently says he’s 42 mg/DL and requesting a second calibration in 15 minutes.

What’s the biggest discrepancy you’ve ever measured between Dexcom and finger stick?


So sorry you guys are going through this Tia. :frowning: It’s so frustrating when all you want to do is go about your day and the tech doesn’t allow you to do that. You know we’ve never had super accurate readings with the Dexcom when it’s reading high or low…when it’s in a nice range, it’s fairly accurate (between 80 - 150). But outside of that range, our Dexcom has never been accurate for us. The G6 is making this a bigger nightmare because if you calibrate it, it spits chunks…

Anyway, to your question - I think the BIGGEST discrepency I ever remember is when the Dexcom read 50’s and he was 290 (via fingerstick). I wrote that off to his BGs reacting to the fast correction he got and the Dexcom just not being “caught up” with his actual sugars yet. But it sounds like this was ongoing for you over time, which is a real pain in the a**.

Are you finding the G6 to be MORE accurate, generally, than the G5? Or less? We’ve only been using it for two days now and last night was really good, but yesterday (the 1st 24 hours after installing it) was off a LOT…and calibrating it caused it to give us 5 separate “come back and calibrate in 15 more min” messages.

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I was completely gob-smacked upon reading your post!!! How on earth are you bolusing for this (and keeping any semblance of calm)? :flushed: :flushed: :flushed:

And in answer to your question, maybe 50-60 points, once or twice maybe more than that…


G6 is way more accurate on average. Usually if the data is wrong it just will say “sensor error” or “no readings” – but it does that waay more often than the G5 did. I also think the insertion is more painful for him and it tends to be more finicky in my experience about the insertion, meaning a bad spot is going to read poorly and die earlier more often.

I honestly wish we could switch to the Libre, as we tried it a few times and Samson found it less painful and equally accurate. It also is supposed to last 14 days, which I think would mesh well with his desire to be pestered and poked as little as possible. Unfortunately, I don’t think there’s a way to Loop with it, right?

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Not to my knowledge

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It did get iCGM certified in 2020, so assume there would be integration soon.