How accurate are glucose meters?

How accurate are glucose meters?. The other day, I did two measurements of sugar blood in a row, (same finger) seconds appart and the glucose meter showed a difference in the numbers.

[WaveRider]

The FDA set meter accuracy at ± 20%. Samples tested seconds apart, the results are always different. Why? Not all blood cells drawn are the same for each draw.

[WaveRider]

The FDA set meter accuracy at ± 20%. Samples tested seconds apart, the results are always different. Why? Not all blood cells drawn are the same for each draw.

[cookieN]

Thank you

[WaveRider]

You're welcome. Because of the ± 20% range home glucose meters can provide only an estimated level. A 140 mg/dl result could mean 168 or it could mean 112, or anywhere in-between. If you maintain a healthy consistent lifestyle, weight, nutrition, & exercise over a 90-120 day period, trust your A1c results.

[cookieN]

However a 140mg/dl meaning a 168 or a 112 makes a huge difference. I have been told that a 168 number is problematic, while 112 is not.

Does A1c averages glucose???? I got a 5,7 result in my last test.

[WaveRider]

Both are problematic as an 112 mg/dl fasting level is considered prediabetes.

"Does A1c averages glucose????"
The eAG [estimated Average Glucose] formula is used to calculate the eAG from your A1c. The formula is:

    28.7 X A1c – 46.7 = eAG

An example of this is your 5.7%. The calculation for this would be:

    28.7 X 5.7 – 46.7 = 117 mg/dl

for an estimated average glucose of 117 mg/dl. Your A1c is .3 [three tenths] of a percent away from classifying you diabetic. For every one percent that your A1c goes up, it is equivalent to your average glucose going up by about 29 mg/dl.

[cookieN]

Thank you