Meter accuracy


#1

I have not yet been formaly diagnosed with diabetes but have been told I have insulin resistance. I have two meters. Walgreens TrueTrack and the One Touch Ultra 2. I was very surprised that the readings from these two meters are consistently 30-40 points off from each other - the TrueTrack is always lower. That is a very big difference. I called each company and was told that the variation between two meters can be as much as 30% and still be considered accurate and that the variation between a blood glucose done in the doctor’s office and a meter should be within 20% of each other.

So I have a meter that tells me. after I eat, my BG is 125 and the other says 165, what do I believe? I think I believe the higher one as I get a jittery feeling after I eat more than 20 carbs.

I will be getting a BG done at the doctor’s office in two days so I will know which meter is closer to that result…if either.

I have done all the tests on each meter to be sure they are working correctly. The test strips and the test solutions are all new. I wash my hands to be sure there are no sugar molecules on my fingertips. Are there other tips to know about getting an accurate reading?

Thanks,
Anne


#2

I have not used a TrueTrack, but my One Touch Ultra and Ultra 2 meters have always been very good when I had them calibrated against lab tests.

It sounds like you are doing the right things with your meters. Is your doctor’s BG test a lab test or just using their office meter? The only real calibration for a meter is to compare it to the results from a lab BG test. I prefer NOT to do my calibrations when I am getting a fasting BG lab test done, because I want a higher reading so the differences will show up better.

Meter accuracy (or lack of accuracy) is always a shock to newbies. There are, as far as I know, no true standards for what accuracy a meter must attain. There is a de facto standard of +/- 20%. but that’s not acceptable if you are trying to keep tight control. The good news is that most meters are far better than the 20% error level, and generally they are pretty consistent. You can deal with a meter that consistently reads high if you know that it does it. Have you done multiple readings at the same time to see how much your meter readings vary?

I like to have 2 calibrated meters that use whatever strip I’m currently using, so I have a backup if I start to doubt my results. Find a meter that agrees well with a lab calibration, and then get a spare (and calibrate it too).

My personal expectation is that my meters should be within 10% of a lab calibration. 5% off is great.

The only meters I’ve had real problems with were the AccuCheck Aviva and theiTest (WaveSence Key Note in US). Funny, because the iTest is supposed to be the most accurate meter around. My first one was more than 20% high against a lab calibration and its replacement seems just as bad, although it won’t be calibrated until midweek.


#3

Have you tried getting a drop of blood wiping it off and then taking the second drop? Try that and see of that makes a difference in your readings. I was not told about this when I was first diagnosed.


#4

i seem to find that the OneTouch is more accurate. Also, the number sounds more like where it should be after a meal.


#5

I also like the One Touch Ultra’s. I have 2 2’s right now. Thinking of getting the mini also
since I have the free coupon. I also make sure that my hands are warm and I never use
the first drop of blood…


#6

Meter accuracy was a big surprise!

I tried using the second drop of blood and I still get a 30 point difference. Thanks for letting me know I should use the second drop.

Doing the test with warm hands is a good hint. I have found it much harder to draw blood when my fingers are cold and they are often cold.

Anne


#7

I have just found out that it is not a good idea to use rechargeable batteries in your meter. I came up with all sorts of readings including a 500 reading when I was actually low. I retested with another meter and got a 67. Boy, am I glad I decided to retest.

If you are going to purchase a one touch mini make sure it is one of the newer ones or wait until the newest ones come out. Old one touch mini only holds 50 readings. That is a real pain when you are having to test 8 or more times a day. Check the back of the box. The newer ones hold 500 readings and the ones that are supposed to be out shortly you will be able to hook it up to your computer and get the readings that way. I like the new lancet device on the one touch mini.

Check with your doctors to see if they have meters to look at or they will give you. The doctors get them for free and then they write rx for the strips. It is always good to have a back up meter just in case.


#8

Two separate drops of blood can be different, using the same meter.
You can have false lows easily I think, but not false highs.


#9

I got my blood tests drawn today. I also had them check my BG with their meter. Now I am confused. My One Touch agreed with the doctor’s meter. The True Touch was only 10 points different. All today the meters have been within 10 points of each other. So why are they behaving today?

Anne


#10

Perhaps they’re in a better mood today!
It’s more likely that you’ve started a different pot of strips (?) Because they do differ a little between pots. Or maybe you just said the magic words!

Doesn’t it drive you mad that they aren’t more accurate? Really pee’s me off!