Differences With Blood Testing Machines

Auckland Canary

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A few nights ago I got home from work and tested my blood and it was 20.5. This really surprised me as I couldn't think what I had done wrong that day .I decided to wash my hands again etc check again just to make sure it wasn't a false reading. This time it came out at 17.9. So obviously I was high but the difference was nearly 3mmol between the 2 readings.

I have 2 blood testing machines so decided to do a 3rd test using the other and this one was 21.1. So this was an even bigger difference I have repeated his test a few times and often get at least 2mmol difference with tests done consecutively.

I wanted to know if people were aware of this because this frightens me if my readings are, say 5 or 6, yet in reality I may be about to have a severe hypo. It makes a bit of a mockery of trying to carb count and adjust ratios if these differences are there in all machines. The margin for error is huge. 1 of my machines is only about 18 months old so I don't think that has a fault in it.
 

mo1905

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Machines can be up to 20% out. They are just a guide. The higher your BG readings, the higher the margin of error. When your levels are 5 or 6, there shouldn't be a lot of error.


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kkkk

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Machines can be up to 20% out. They are just a guide. The higher your BG readings, the higher the margin of error. When your levels are 5 or 6, there shouldn't be a lot of error.


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Yep I would 2nd this…they are a guide and the margin for error is bigger the higher you are, and just to throw this one into the mix I read that there is some evidence that it is not necessarily just how low you go but how long you are low for that can cause things like fits and nasty stuff like that in hypos (though not one to test!)
 

noblehead

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I'm sure also that the bg meters are more accurate the lower the bg readings, so your concerns about such a margin of error at hypo levels need not be.

If ever in doubt do a control solution test or simply replace the meter, if your type 1 and say you test 6+ times a day the meter manufacturers will throw their meters your way, only ever paid for one meter and that was my first.