Differences between meter readings

bkendall · #1 (**permalink**) 11-15-2009, 07:34 PM

Hello. I've been lurking for a while but this is finally my first post.

I've been through several meters over the two and a half years since being diagnosed with Type 2. I haven't found one that I love yet (if such a thing exists), and right now I'm using an Accucheck Aviva. It's been reading higher than normal for me recently, and I was worried that it may be off.

Today I ran out and picked up a OneTouch Ultra Mini while I was at work, and it was giving me off-the-chart readings.

Once I got home, I compared the Aviva and UltraMini readings side by side and the Aviva was consistently 30 to 40 points lower.

In the past I'd compared the Aviva to a Kroger meter and it was also 30 to 40 points lower every time.

Is this a normal thing with these Aviva meters?

It's confusing for me, because readings with one meter are OK and are too high with the other... Considering the Aviva is lower than every meter I've compared it to, I'm beginning to think that it's the problem, not the other meters.

Accucheck is sending me some control solution to make sure that my meter is within range, but I'm concerned because for any particular reading, one meter says I'm alright and the other says I'm too high.

Any insight out there?

Thanks!

ShottleBop · #2 (**permalink**) 11-15-2009, 09:56 PM

Dr. Bernstein, author of The Diabetes Solution, continues to recommend the Accu-Chek, which, I've heard/read, typically runs 5% or so on the high side--and Jenny Ruhl has blogged, over at Diabetes Update, of the possibility of missed hypos because it runs high. When I bought an UltraMini, shortly after diagnosis, it routinely gave me readings that were 10-15 points LOWER than my Aviva. So did the TrueTrack and TrueTest meters I bought. The WaveSense Presto has given me readings pretty much in the same ballpark as the Aviva.

And remember, with a 20% tolerance for accuracy, it's entirely possible for two meters to be working within tolerances, and to be 40 points apart.

mortis505 · #3 (**permalink**) 11-15-2009, 10:30 PM

How does the Aviva jibe with the meter your Dr uses. I had problems with the Aviva always reading me in the 90s while my Onetouch meter read me in the 70s.

ramon · #4 (**permalink**) 11-15-2009, 10:37 PM

Quote:

Originally Posted by mortis505

How does the Aviva jibe with the meter your Dr uses. I had problems with the Aviva always reading me in the 90s while my Onetouch meter read me in the 70s.

This is very confusing, took several readings at one time on the same meter and none matched. As much as 18 apart.

ShottleBop · #5 (**permalink**) 11-15-2009, 11:07 PM

Quote:

Originally Posted by mortis505

How does the Aviva jibe with the meter your Dr uses. I had problems with the Aviva always reading me in the 90s while my Onetouch meter read me in the 70s.

It's always been within a few points of the lab reading.

jtausch · #6 (**permalink**) 11-15-2009, 11:12 PM

I use the accue chek aviva and it was only 1 point lower that my lab check taken from the same sample they used

REDLAN · #7 (**permalink**) 11-16-2009, 12:04 AM

there are a few things....

1) buy some testing solution and test the meter and see whether it is working within limits. If it fails I don't think they can be recalibrated I think you have to buy a new one.

2) Meter accuracy - often debated on this forum. What manufacturers use to assess meter accuracy is a Parkes (or Consensus) Error Grid. They measure 100's of blood tests on their meter and also take a venous sample to be analysed in the lab. They then plot the variance on a grid divided into 5 zones - each zone is graded according to how much of difference it makes to treatment. The vast majority of results fall into "makes no clinical difference" part of the grid. A few fall into makes a bit of difference, and the odd one or 2 fall into might miss a high or low.

3) a 30-40 point difference between meters - is in reality quite small. It is around the potential error of a typical meter. From a PDF I've seen the accucheck do typically seem to read lower than other meters. Meter's are calibrated to work in a small range of BG - any differences between them will tend to diminish at lower BG's.

The answer is to pick a meter you are happy with and stick to it, generally one meter will produce reasonably consistent results.

Abra · #8 (**permalink**) 11-16-2009, 01:56 AM

This is interesting to me because the only meter I've ever used is the Freestyle Freedom Lite - it's what my Dr. gave me at Dx. Any experience with how this particular meter compares with others?

bkendall · #9 (**permalink**) 11-16-2009, 04:06 AM

Quote:

Originally Posted by ShottleBop

And remember, with a 20% tolerance for accuracy, it's entirely possible for two meters to be working within tolerances, and to be 40 points apart.

That just seems crazy to me, because a reading on the Accucheck of 119 six hours after a meal is normal for me, but the Lifescan reads 158 at the same time, which is high.

I guess the only thing to do is test blood when they take labs and compare the results?

JoanW · #10 (**permalink**) 11-16-2009, 10:40 AM

Quote:

Originally Posted by bkendall

That just seems crazy to me, because a reading on the Accucheck of 119 six hours after a meal is normal for me, but the Lifescan reads 158 at the same time, which is high.

I guess the only thing to do is test blood when they take labs and compare the results?

One thing that no one has mentioned so far is "did you code the One Touch according to the number on the can of strips?". I use an Accu-Chek Compact, and do not have to code it, but I know the One Touch meters need coding...

foxl · #11 (**permalink**) 11-16-2009, 10:47 AM

My Aviva ran much higher ... and SO did its copay! It is in the linen closet, now ...

bkendall · #12 (**permalink**) 11-16-2009, 11:32 AM

Quote:

Originally Posted by JoanW

One thing that no one has mentioned so far is "did you code the One Touch according to the number on the can of strips?". I use an Accu-Chek Compact, and do not have to code it, but I know the One Touch meters need coding...

I sure did.

I've made an appointment to see the doctor on Wednesday, and I'm going to talk to him and see what he thinks. My last bloodwork was in April so I'm due for another A1c.

How do I compare the meters to the A1c reading? Do I do a normal test at the time of the lab collection, or do I ask them to provide me with a collected sample to test with since it's from a vein and not microcapillaries?

Thanks!

Edit: Typo

ShottleBop · #13 (**permalink**) 11-16-2009, 12:15 PM

Just do your normal finger-stick test at the time you give blood.

genie86333 · #14 (**permalink**) 11-17-2009, 06:50 PM

I have an Aviva & have found when my blood sugar is higher(over 120) that the Aviva runs 20-30 points higher than my other meters) but when it's lower, the Aviva runs 15-20 points lower than my other meters (the other meters, both TrueTracks, are always within 5 points - usually within a point or 2- of each other.) So...I don't trust it & went back to the TTs.