Different reading by blood glucose meter

[biren1973]

Hi

I'm sure people in this forum might have seen this before. I am using SD codefree blood glucose meter for my measurements. What I found is this meter is giving me two different results just with in a span of less than 1 minute. Is it correct or do I need to change it?

First it gave 6.3 morning fasting measurement then after 10 seconds when I retested it showed 6.1.

Regards

 

[azure]

That's normal @biren1973

Your meter will give slightly different results if yountest three times in a row or whatever. Don't worry about it as long as the figures are all in the same bal-park and not wildly different.

 

[marathonmona]

My Codefree gave me 7.3 on my left hand and 5.1 on my right hand yesterday pre-meal!
WTH?

 

[azure]

My Codefree gave me 7.3 on my left hand and 5.1 on my right hand yesterday pre-meal!
WTH?

That's normal too It's a snapshot not an exact measurement. You'll get different measurements from different fingers and from the same finger testing twice.

 

[Fleegle]

I do not think you need to replace your meter.

There are so many variables it is difficult to know where to start. I have done quite a lot of testing and reading and used test solutions and I have even done 10 tests one after the other. It is frustrating at times.

There is absolutely nothing wrong with a 6.3 and a 6.1. ,2mmol is just an error rate that is perfectly acceptable.

These are the things that I found impacted me:-
Clean fingers
The soap I used.
First or second drop of blood.
The strip - you only have so long it should be exposed to air for.

And then - meters have to be within 15% accurate 90% of the time.

I think the best advice I could give if you want to test twice is to test with the same finger - same stab - first and second drop. The second drop should be more accurate than the first.

 

[biren1973]

My Codefree gave me 7.3 on my left hand and 5.1 on my right hand yesterday pre-meal!
WTH?

So which one is true? Anything wrong with the machine?it can't be that much difference, right?

 

[Bluetit1802]

1. Our blood rushes round our bodies at lightening speed. What was there one minute is not there a second later.
2. Each haemoglobin cell (and they are microscopic in size) will have a different amount of glucose attached to it. Each test will be from different haemoglobin cells, even if you use the same drop of blood..
3. Our meters, whichever brand, have to conform to the same accuracy standards, which allows an error tolerance of plus or minus 15% in 95% of the time. The other 5% they can be miles out.
4. There is no difference at all between 6.1 and 6.3 @biren1973
5. Either of the 7.3 and 5.1 could be true, and neither could be true @marathonmona A third test might have helped.

 

[Fleegle]

1. Our blood rushes round our bodies at lightening speed. What was there one minute is not there a second later.
2. Each haemoglobin cell (and they are microscopic in size) will have a different amount of glucose attached to it. Each test will be from different haemoglobin cells, even if you use the same drop of blood..
3. Our meters, whichever brand, have to conform to the same accuracy standards, which allows an error tolerance of plus or minus 15% in 95% of the time. The other 5% they can be miles out.
4. There is no difference at all between 6.1 and 6.3 @biren1973
5. Either of the 7.3 and 5.1 could be true, and neither could be true @marathonmona A third test might have helped.

Yes I completely agree - if I had two reading vastly different like that (and therefore of no use) I would do a third and try and work through what is going on. I personally suspect that one of the fingers was slightly contaminated maybe.

 

[badcat]

I agree. My one touch ultra ( usually v consistent) just gave me 11.3, 9.1 and 8.4 in the space of 2 mins.
I obviously prefer the last one Its not just the best but also the one that makes most sense given I started out on a 6 and have only had 11g carbs so far.
General message is they are all higher than wanted / expected so keep an eye on it

 

[Scott-C]

it can't be that much difference, right?

Why not? Your blood stream is an incredibly complex plumbing system, arteries, capillaries, arterioles. It would be surprising, a fluke, if concentration of glucose in all parts of it in different areas of the body was the same.

Meters don't weigh glucose like a set of scales. The strips break down glucose into other chemicals, measure the electric current coming off that and make an educated guess as to what that amount of current means in relationship to glucose concentration.

All you're ever going to get is a ball park, near enough number.

You can still buy Glucoflex-R colour changing strips on the internet. Before meters, we put some blood on a strip, waited a minute, wiped it off, waited another minute, and then compared the colours to a chart on the vial. If it was a nice light tan/light blue, that was a good five. Decimal points didn't play a part in this.

Welcome to the wonderful world of metering uncertainty!

 

[marathonmona]

1. Our blood rushes round our bodies at lightening speed. What was there one minute is not there a second later.
2. Each haemoglobin cell (and they are microscopic in size) will have a different amount of glucose attached to it. Each test will be from different haemoglobin cells, even if you use the same drop of blood..
3. Our meters, whichever brand, have to conform to the same accuracy standards, which allows an error tolerance of plus or minus 15% in 95% of the time. The other 5% they can be miles out.
4. There is no difference at all between 6.1 and 6.3 @biren1973
5. Either of the 7.3 and 5.1 could be true, and neither could be true @marathonmona A third test might have helped.

@bluetit: yes in future, if a big difference like that presents itself, I'll test thrice