Hello All,
I usually get numbers from my fourth and second finger to enter in CGM for new censor calibration,question is why some time numbers are 30 digits apart and within time diff of max 5 second!!
The standard that controls BG meter accuracy only requires +/- 20% or +/- 15% from the actual value 95% or 99% of the time when over 75 mg/dl. So if using the tighter standard and your actual BG is 100 mg/dl, the standard considers it accurate if you read anything between or equal to 85-115 mg/dl. Standards are in flux right now. You can read up on this topic by googling “home blood glucose monitor standard.”
Home blood glucose testing meters have never been lab-worthy accurate. If your meter dependably clusters your readings within a relatively tight range (also know as precision) then that makes the meter reliable enough to depend on.
I will often do two consecutive fingersticks and simply average them and use for treatment.
I do similar when I calibrate a new sensor - same finger position, different hand.
Our blood is not homogenous. Add to that the inaccuracy of even the most accurate BG meters and you will see a difference like you have described. Sometimes when I see that large of a difference, I will take a third reading from one of the same fingers. I typically get a number very close to the first one taken from that finger.
I’ve tried checking my numbers from the same exact blood sample and gotten up to 20 points different reading! I prick a finger and draw a large dot of blood and check, then use the same dot for another reading right after the first…and totally different numbers. I’ve done this with four different monitors on many, many occasions and always the same largely different results. So, yeah, BG for me is just an approximate number, a range, never exact. This is why I check often, because you never really know.