Why some meters work better with Dexcom G4 than others

I ran into my sales rep at the hospital today and he told me that the Dexcom G4 is calibrated (or did he use another word for it?) with/at Yellow Springs Instruments. Therefore meters calibrated at/with the same system will be more accurate than others when you use them with the Dexcom.

The meters/manufacturers he knew was using Yellow Springs Instrumenst was Freestyle from Abbott.

Bayer does not use Yellow Springs Instruments and that could be the explanation to this discussion.

This was just a quick two minutes chat, and I donĀ“t recall all of the information exactly as I was told, but I think I got the most important points.

Thought it was worth sharing.

Interesting, thanks.

Thanks! That makes sense. My Dexcom G4 has been super accurate and I use the Freestyle in my Omnipod PDM.

I am sure its all about dollars and cents. They probably have a patent on that tech and others have patents on their own. As usual the patient/enduser loses.

Mine too, much more accurate than my 7+

I am not sure your logic is completely correct for comparing the calibration of the Dexcom with the calibration of another instrument.
That is like comparing apples to oranges.
You are taking measurements from any Blood Sugar meter and then inputing that data into the Dexcom. The Dexcom doesn't measure blood sugar. The dexcom only measures the change in the interstial fluid. It does not measure the blood sugar.
So if you insert a blood sugar reading, then it calibrates to that reading you insert. It has nothing to do with the actual blood sugar. You could for example, enter in a blood sugar always 50 points higher than any reading on a blood sugar meter, and then your Dexcom will constantly read a number 50 points higher.

The Blood Sugar meter you purchase in the store, to be accurate should be sent back to Yellow Springs every 12 months to make sure it is calibrated, and when it is suppose to be measuring 1volt, it is getting 1 Volt, +/- 0.2Volts, remember the accuracy from the ADA for Blood Sugar meters is +/- 20%. So every Blood Sugar meter in true honesty is just a guess. Yes, they are probably in the accuracy of 5-8% most of the time. But if your battery is on the edge, and the humidity is on the edge, and the temperature of the room is at the edge and all of the other factors are at the edge, you blood sugar meter,no matter which one you use, is going to be giving you a bad reading.

That is why the Dexcom is best at seeing trends not actual blood sugars

Hey JM,

Just came across this thread and your post, as I've been unhappy with the accuracy of my OneTouch meters and have been researching possible alternatives.

You mentioned sending meters to Yellow Springs to make sure it's calibrated, which I've never heard of before; so you definitely piqued my interest! Can you please elaborate on this a bit? I did a decent amount of research but wasn't able to find anything more about how that works (e.g. where to send the meters to, how much it costs, whether they actually calibrate the meter or just check if it's already calibrated, etc.)

If anyone else is familiar with this as well, please jump in!


Mark - same here. I have been using the One Touch Verio Sync for a while and I haven't been happy with the overall accuracy (seems to run about (15-20% higher) so I just picked up the Freestyle Precision Neo. Will let you know how it goes after using for a little while.

Thanks Mike. I'm following Jake's post about the Neo, so feel free to post your results there and I'll see them

Curious, what made you go with the Neo and not the FreeStyle Freedom Lite, which Dr. Bernstein and many people on here recommend?

BTW, you posting a response is almost akin to a celebrity retweeting my tweet :)

LOL thanks Mark.

Honestly, no real reason to choose one over the other. Both Abbott meters so I figured I would give the Neo a try.