Diabetes Testing

Comparing Meter Accuracy

Anyone who has been trying to control his or her diabetes for more than a few days often gets disappointed with checking blood glucose levels. Our disappointment is sometimes not how high those levels go but how erratic our meters and test strips seem to be behaving.

Meter accuracy is a pain — an emotional pain that can be more than the physical pain of lancing. Just which meter systems are accuracy?

That’s probably the question that people newly diagnosed with diabetes ask me the most. And now for the first time we have the beginning of an answer.

In my 15 years of following diabetes developments I haven’t seen a single scientific comparison of the blood glucose meters that we have to work with. Until now.
And now we have a study that compares meters from the major brands as well as some minor ones. The study compared 27 blood glucose monitoring systems including systems from the big four on the American market, LifeScan, Roche, Bayer, and Abbott. These are the four companies that seem to have a lock on reimbursement from almost all medical insurance plans.

Strangely, the study appears without fanfare. I only learned about it from an executive of i-SENS, the Korean meter manufacturer that invited me to visit South Korea last month. i-SENS makes blood glucose meters and test strips for many other companies that sell them under their own names, and I don’t know which, if any, of the meter systems that the new study evaluated came from i-SENS.
The study appeared in the February 2010 issue of Diabetes Technology & Therapeutics as “System Accuracy Evaluation of 27 Blood Glucose Monitoring Systems According to DIN EN ISO 15197.” Even better news is that this journal’s publisher, Mary Ann Liebert Inc., is providing complimentary online access to the full-text of three of its publications through the end of November in honor of World Diabetes Day, which was on November 14. In addition to Diabetes Technology & Therapeutics, this includes Metabolic Syndrome and Related Disorders and Childhood Obesity. You can read the full-text of the meter accuracy study at http://www.liebertonline.com/doi/pdfplus/10.1089/dia.2009.0128.
At first glance the study may not appear relevant to Americans, because it evaluates the systems according to European standards. But the fact is that the U.S. Food and Drug Administration has de facto adopted those standards for the U.S.

The European standards are that at least 95 percent of our blood glucose test results have to fall within plus or minus 15 mg/dl of the true result when the level is below 75 mg/dl. The standard allow a little more leeway at higher levels. Our test results have to fall within plus or minus 20 percent when the level is above 75 mg/dl. That’s simply because test results at lower levels are critical — particularly in terms of insulin dose — so these standards make sense.

The good news is that blood glucose systems from three of the four major meter manufacturers fulfilled the European requirements. Five meters from the big four fulfilled the requirements 100 percent. These are Roche’s Accu-Chek Aviva and Accu-Chek Active, Abbott’s FreeStyle Freedom and FreeStyle Lite, and LifeScan’s One Touch Ultra2. Also scoring 100 percent were two meters from a smaller company, Bionime.

In total, 16 of the 27 systems in the study fulfilled Europe’s minimum accuracy requirements. That means, of course, that more than 40 percent of them simply aren’t good enough. Quite a few of these meters are, however, not even sold in the U.S.

We knew, of course, that our meters in general aren’t good enough. And now we know which ones that we can tend to trust.

Anyway, I do encourage you to read the system accuracy evaluation study. At a minimum, please note the tables on “BG Monitoring System Accuracy Results” and “Clarke Error Grid Analysis.” Then, you may want to get a meter to replace the old one that you have been using.

This article is based on an earlier version of my article published by HealthCentral.

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  • Reply Baquar July 1, 2015 at 1:26 pm

    also I would like to add that I got blood sample from same finger.

    readings are higher compared to one touch ultra2

    appreciate your advise

  • Reply Baquar July 1, 2015 at 1:23 pm

    Hi David, just now I got Accu-check Active but unfortunately when I carry out continuous test may be three times it shows me three different readings like 171,182 and 161, any comments on this.

    • Reply David Mendosa July 1, 2015 at 2:12 pm

      The differences of those readings do look like a lot, but in terms of percentage they are acceptable. The differences are acceptable. Whichever the correct number is is not acceptable. Far too high! The rules that the manufacturers have to follow allow a greater degree of range for really high numbers like yours than when the number is low. That’s because smaller differences in numbers, when levels are, say, below 90, could be really troublesome if it was actually below, say, 60. So you may need to see your doctor to adjust your medicine. Of course, you must reduce the amount of sugar and starch that you eat, which is what makes your blood sugar levels so high.

  • Reply Jeremy June 2, 2015 at 9:55 am

    Hi David,

    I just got the accu-chek nano (newly diagnosed diabetic) and have been experiencing readings from the same lance that vary enough to be disturbing. For example: reading one 349, second reading 291 just moments ago. I’m trying to find out if I’ve got a defunct reader, bad strips, or doing something wrong. Could you send me the PDF of the study?


    • Reply David Mendosa June 2, 2015 at 8:47 pm

      I sent the study to your email address, Jeremy.

  • Reply bernard November 20, 2012 at 10:05 am

    Thanks David,
    Got the file and update

  • Reply bernard November 20, 2012 at 10:04 am

    Thanks David, I have returned the tester which was purchased 2 weeks ago.
    Is it possible to get the PDF sent to my email as well? Appreciate it and would like to see results from the tests

  • Reply bernard November 19, 2012 at 6:15 pm

    Hi David,
    I have had over 20% difference with a friend’s tester and mine, exact same brand (roche performa) and it is really worrying when your fasting is 99 or 120 at the same time with 2 identical testers. Is this really acceptable?
    Could you please send me the PDF as well
    thanks a lot

    • Reply David Mendosa November 20, 2012 at 8:07 am

      Dear Bernard,

      No, that’s not an acceptable difference. But sadly we still see such errors.



    • Reply David Mendosa November 20, 2012 at 8:08 am

      Dear Bernard,

      No, that’s not an acceptable difference. But sadly we still see such errors.



  • Reply Joe Zak August 30, 2012 at 2:13 pm

    Thanks David for the file!

    What about the Contour USB meter?
    Any feedback on it?

  • Reply Joe Zak August 30, 2012 at 11:15 am

    I would also like a pdf copy of the 27 meters comparison study please…I was only able to download the other study comparing 5 devices at:

    Also, would like your opinion on the Accu-Check Nano & Contour USB meters’ performance and accuracy…Thanks a lot for your help!

    • Reply David Mendosa August 30, 2012 at 11:31 am

      Dear Joe,

      I just emailed you a PDF of the study.

      But I haven’t evaluated the Nano meter.


  • Reply John June 11, 2012 at 10:25 am

    Hi, can I get a copy of the PDF as well? Thanks.

  • Reply Quin Yang April 15, 2012 at 11:49 pm

    Hi, David:

    Please send me a copy of this glucose meter comparison article too. Thanks.

    • Reply David Mendosa April 16, 2012 at 2:46 pm

      Dear Quin Yang,

      I will send you a copy by email when I return home. I am traveling right now.


  • Reply Peter Ting March 18, 2012 at 12:20 am

    Dear David,
    The 27 glucometer comparison trial based on ISO15197 has one problem that’s not been highlighted ie as the test results is done based on fasting blood glucose readings, it does not address the problem raised by the non-glucose interference caused by using the reagent GDH-PQQ in the test strips. These problems may not be significant in the US but meters using this GDH-PQQ reagents are still widely available outside the US.
    Peter Ting

  • Reply Frank Turner February 28, 2011 at 7:14 am

    I have been given 2 Accu-check Performa nano meters. One for home and one for work. They both read about 20% higher then my other meters. Any thoughts on this and your view on the Nano.

    • Reply David Mendosa February 28, 2011 at 8:04 am

      I don’t think that the Nano is available for sale in the U.S. At least I have never seen one. I do know that the Accu-Chek Aviva, which is one of the most accurate meters, tests higher than LifeScan meters. I trust the Aviva readings on the basis of my reading and experience with them.


  • Reply Annette Priestley February 22, 2011 at 10:08 pm

    I would also like a pdf copy of the meter article as my meter can vary a lot of points within 30 seconds of use. Thank you. Annette

  • Reply Virginia February 17, 2011 at 11:10 pm


    Would you please send me a copy of the article too. I tried getting it with my student ID, but it is unavailable at the unversity I attend. Thank you.


  • Reply Maggie Lesoing February 4, 2011 at 10:52 am

    Hi David, I’d love to get a copy of this article, also. We are on a pretty tight budget but having the best info about meters is really important! I’ve requested it from our local library but I don’t know if they’ll be able to get it. Thanks in advance!

    • Reply David Mendosa February 4, 2011 at 8:41 pm

      Dear Maggie,

      It’s on its electronic way to you right now!


  • Reply David Mendosa January 22, 2011 at 10:14 am

    Right now I am using the Mendor Discreet, which I just reviewed (and isn’t yet approved for use here). The meters I use are the ones I write about here and at healthcentral.com


  • Reply fiftyate January 22, 2011 at 10:07 am

    david, what are some of the newer meters you are now using? i respect your opinions over the sales reps from the manufacturers. thanks fiftyate

  • Reply David Mendosa January 22, 2011 at 9:59 am

    The AgaMatrix meters are among the most accurate. But I generally use any one of the newer meters that companies send me for review.

  • Reply fiftyate January 22, 2011 at 9:47 am

    david, a couple years ago you highly recommended the aga matrix meters. since then i haven’t heard any more about them. do you still use this brand? thanks, fiftyate

  • Reply alyssacr January 14, 2011 at 9:36 am

    I can’t seem to get the article, but I’d love to read it. Was it only free until 11/14/2010? That’s a bummer, if that’s the case.

    • Reply David Mendosa January 14, 2011 at 4:25 pm

      I just sent you a copy of the PDF to your email address.


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