Meter Accuracy Issues

TeetooMac
By TeetooMac Latest Reply 2013-06-11 12:58:00 -0500
Started 2010-01-31 16:46:26 -0600

I just got out of the hospital on a non-diabetes related issue and discovered during my stay how different the hospital meter and my meter were for the daily periodic blood glucose testings. Sometimes the meters within 10% and sometimes off by 35%. This is scary. Then we tested a finger on my other hand within minutes and got results totally different from our original finger stick. BTW: We drew blood from the same finger stick on every occasion. Have you had similar situations? What does this say about the general accuracy of our home meters compared with the hospital ones that are calibrated almost daily?


9 replies

gatp
gatp 2012-05-11 12:49:08 -0500 Report

It is not unusual to get different results in each hand but not 35% different. I am a fprmer lab manager. Many things can cause this, such as blood pressure, can be different in each arm or the size of the drop or the size of the drop of standard can be off. The main thing is that the hospital tester ought to have good reproducibility with their monitor. I was told by my doctor that the exact number is not as important as the daily curve. If is higher for a few days, you need to figure out why.

Hinboyz3
Hinboyz3 2010-02-01 07:11:38 -0600 Report

Im with everyone else the ones from the hospital are different, than the ones we use at home on a daily basis.

kdroberts
kdroberts 2010-01-31 19:49:19 -0600 Report

It's a complicated thing really. Hospital meters are not 100% lab accurate, there is one that is very accurate but it still has a margin of error. The calibration doesn't really have much to do with it but the way they test the blood and display the results is. A lab will take the blood drawn from a vein, spin it until it splits and then measure the concentration of sugar in the plasma. With home meters and the meters used in hospitals that take blood from the finger they use various chemical reactions and electrical conductivity tests to get a whole blood result then use various calculations to display the result as a plasma equivalent. You also have to deal with temperature, blood sugar quickly changing, concentration of blood, etc so it is a lot harder to get accurate results on a small, cost effective meter for home use.

The basic US standard right now is +/- 20% of your actual blood sugar (not readings) if your blood sugar is over 75 mg/dL or +/-15 points if your blood sugar is under 75 mg/dL. Most meters can be a lot more accurate than that but not 100% of the time.

Jesse's derby
Jesse's derby 2013-06-11 12:58:00 -0500 Report

You are right. I just switched to the "cost effective" Walmart meter and strips. My readings have been completely off the wall! I have been comparing the numbers with a different machine and there is quite a difference!

ptsparkle
ptsparkle 2010-01-31 19:23:49 -0600 Report

TeeTooMac,
I wouldn't worry about it. If your numbers are good with yoiur meter at home, then your A1c should reflect that.. If not, then I would look into it further. All meters vary, so you just have to test often and ck. your 1c
Jim

TeetooMac
TeetooMac 2010-02-01 15:23:13 -0600 Report

Thanks for your reply! I'm not personally worried even though the procedures took my BG up over 400. My A1c was last measured at 5.3% so I'm not in a big worry state. However, if my meter at home says I'm at a number considerably higher than in the hospital and that number is much higher than actuality, is it not true that I could over-compensate and take too much insulin that could result in my having a severe low? That's the only scary part and it's not that I'm personally worried…

alanbossman
alanbossman 2010-01-31 18:44:37 -0600 Report

Hi TeetooMac most meters for our use are anywhere form 10% to 25% off. The reason is the meter companys are allowed to do this. The companys say if the meters were 100% correct the cost for those meters would be higher in price.

MAYS
MAYS 2010-01-31 16:58:06 -0600 Report

Hospital meters are calibrated daily (as is most of their equipment) and the accuracy is as close to perfect as possible, the margin of acceptable error is outside of our human comprehension.
The standards and parameters for the hospitals equipment is much different than that of the meters for consumer use although they achieve the same final results although that may not seem to be based on what we see.
I just had this very same discussion with a friend of mine who works in the hospital calibrating the electronic medical equipment, I'm assured it's nothing to worry about but I can't help but wonder !