Unreliability of the meters

[Mike Sixx]

I did not eat well today and I was feeling a bit feverish. I ate cafeteria sandwich, whole grain rye with veggies, cheese and fried egg. One in my "morning" 12:00 and another at 16:00. That's all I had to to eat all day.
Coming home at 19:00 I measured my BG. And it showed 7.3mmol I was did not believe it even though I had washed my hands. So I squeezed another blood drop form same wound and not the NHS (Finland) ****** Chinese meter showed 6.6 . Still not trusting it so I washed my hands again. Used a new needle and measured with Contour Next meter and it showed 8.3 ! I measured again from the same blood drop with the Chinese **** meter 6.6. Then again with Contour and it was 7.9.

So from same blood drop I got 8.3mmol and 6.6mmol with different meters. And 5.7 and 7.3 with same meter.

So Bauer Contour NEXT error margin 5% and that cheapo-china-**** 14%
Both what to be expected, but when compared to each others it is 25% error margin.

That was more than my usual carb amount and it self was my mistake (I am fairly new to T2 so still learning my limits) but that is besides the point. Also besides the point is the reason why I am mixing the meters. I bought the Bauer myself and got the cheap-o meter and strips for free from NHS. I am using the Chinese meter and strips to measure meals and the good with more expensive strips for Fasting values. This way I also get more meaningful history as the apps mess up after meal and fasting values in history. (That and the strip price being the only drawback of the Contour NEXT).

P.S.
30min later 6.5 with china meter and 6.8 with Bauer. Which is what I was expecting.

 

[millenium]

I am using a Chinese meter that uses thicker strip and need a bigger drop of blood. It is very accurate.

 

[Mr_Pot]

I am using a Chinese meter that uses thicker strip and need a bigger drop of blood. It is very accurate.

How do you know?

 

[TooSweetForMe]

And where do you find Chinese blood glucose meters? I'm in the US and have never seen them anywhere.

 

[millenium]

How do you know?

After I test my father bg level, I test my own in the beginning stage when i first switched to the new machine. This is in fact the upgraded version of the old model that is found to be quite reliable against clinic reading. The old one has a margin of error of 20% and the new one 10%. As I am non diabetic, it is quite easy to judge if a reading is a reasonable one. As for my dad, I have very detailed records of his fgl and his 2 hours post meal bg after different type of meal intake (I weigh the food every time), so I can tell if a reading of his is way out of normal. So far there is none.

 

[millenium]

And where do you find Chinese blood glucose meters? I'm in the US and have never seen them anywhere.

I buy from China platform taobao. The stripes cost only less than usd0.2 each and the machine is free of charge. But u need to buy the correct model to get a reliable one.

 

[Mike Sixx]

I am using a Chinese meter that uses thicker strip and need a bigger drop of blood. It is very accurate.

My cheapo one says GlugoX - Taldoc Technology Corporation. And it's actually Taiwan if that makes much difference.

My point was it made almost 1 mmol error from SAME blood drop. And almost 2 mmol error to German made meter.

 

[millenium]

My cheapo one says GlugoX - Taldoc Technology Corporation. And it's actually Taiwan if that makes much difference.

My point was it made almost 1 mmol error from SAME blood drop. And almost 2 mmol error to German made meter.

If I have doubts on the accuracy of he device, I would also do that. I measure three times, one after another and compare the three readings.

If the machine manual says 20% variance, the margin for difference can be quite large.

My old China meter which has a variance of 20% is actually quite accurate already from my experience. From there, the manufacturer actually increase the width of of the strip to reduce the variance to 10%. One will need a much bigger drop of blood to get a reading because the blood inlet on the strip became wider also.

 

[Rustytypin]

I have four different meters, and occasionally check one against the other and find that they can differ by up to 1 mmol from the same drop of blood. The max number at one time is a comparison between 3 meters, not managed to do all four at once! Although the Tee2 is usually higher at the moment than the others, a few months ago it was consistently lower.
These days I don't stress too much at the differences between meters, and use just one at a time for the duration of a pot or two of strips, depending how many I have ordered at the time. Also do not test every day now.

 

[KK123]

Yep, I have tested and experimented over the years with a variety of meters and now use the same one always because at least it can show me a trend if not much else. Add to that it can make dosing tricky because if I am at 7 nudging towards 8 I would take a unit of insulin but I have to double (and sometimes triple) test because I don't want to assume it is actually 7 and take a unit if it is actually low 6s!

 

[porl69]

The moral of this story is to use 1 meter and 1 meter only
There is a tolerance on BG meters of 15%. If your bloods were 7mmol then all of those readings would be in tolerance!

 

[Mr_Pot]

I have not been able to discover exactly what the accuracy means. Although meters have to be within +/-15% of a laboratory reading does that mean that a particular meter would be say 10% high all the time or sometimes up to +15% and sometimes up to -15%?

 

[porl69]

I have not been able to discover exactly what the accuracy means. Although meters have to be within +/-15% of a laboratory reading does that mean that a particular meter would be say 10% high all the time or sometimes up to +15% and sometimes up to -15%?

Your meter could give you a -/+15% reading on the same drop of blood and still be within tolerance. Mad I know

 

[slip]

And BG levels are not constant throughout the body, the first drop of blood *might* contain 7.6mmol but the second drop might have 10% more.......or 10% less........or.......

 

[Mike Sixx]

My point was "It was quite accurate to my opinion" could just mean it gives consistently wrong readings. As I noticed when comparing 2 meters. Each were within 15% error margin by themselves, but pushing close to 30% erro margin when compared with each others.