That "accuracy" was actually pretty decent

Stick test meters only have to be within 15% of a lab sample - so if your labs said 100 points, the FDA or whomever approves the standards says if the meter reads anywhere between 85 and 115 that is "accurate enough"

The best meters on the market are between 5 and 10% variance from a lab sample

Now that may sound like too much, but as long as the meter or the CGM as the case may be is "always" 5% low that's ok, you can work with that

I wear the Libre2 and last year the day of my A1C test the APP calculated that my my A1C would be 5.6% and it was bang on - this year it said "5.8" and that's exactly what the lab said

Now CGM's measure blood sugar in a "different place" (fluid around the cells) then a "stick test" which measures sugar in "whole blood" (from a capillary) and a Lab Sample is run against Blood Serum

3 methods, measuring 3 different places and unless your blood sugar is perfectly stable it will always be different in the plasma compared to the whole blood compared to the interstitial fluid

So it's not that it's inaccurate- it's just telling the "current level" in 3 different places as the sugar migrates from the main arteries to the capillaries to the cell fluid

It should be different because the sugar migrates at different time intervals - from whole blood to cell fluid it takes "about" 15 minutes to get from one to the other and then for the cells to burn it up

And while it may sound wild, your blood sugar can swing 50 points "in seconds" as it's transported either into the cells or stored in your muscles

So when you take a CGM reading it is showing you what the "stick test" either showed 15 minutes ago OR where it will be 15 minutes from now

Comparing apples and banana's and trying to measure one against the other causes distrust and confusion

I use the freestyle libre 3. I like the ability to check on my blood sugars whenever i feel i need to. I can also see how what i ate affected my sugars.