15 Responses

  1. Michael Ratrie
    Michael Ratrie July 8, 2010 at 7:29 am | | Reply


    I would have to say that my gut reaction is that Roche wants to ride its current strip technology for as long as it can and that this is a significant driver in their “range” concept. I felt the same way when you posted the Roche “White Paper”, which is generally good (who can argue with better accuracy?), but has a “marketing-feel” to it.

    In short then, Roche needs to address the PQQ “issue”.

    FWIW, I would vote for 10/20, because that gives you greater accuracy at the low end while leaving the high end unchanged from what we currently have. My guess is that Roche can do any one of these steps way more inexpensively than redesigning their strips to reach 10/10.

    Fair Winds,

  2. Leighann of D-Mom Blog
    Leighann of D-Mom Blog July 8, 2010 at 8:37 am | | Reply

    Will the regular Freestyle strips that are used in the OmniPod PDM also have this new wicking tabs?

    We’ve transitioned to using the OmniPod PDM to test blood sugars and use the regular, not Lite strips now.

  3. Leighann of D-Mom Blog
    Leighann of D-Mom Blog July 8, 2010 at 8:40 am | | Reply

    If I’m reading the Abbott press release right, the FreeStyle strips (in addition to the FreeStyle Lite) will be compatible in all of their meters and also have the wicking tab and do not do not use the GDH-PQQ1 enzyme.

    Am I reading that right?

  4. Ginger Vieira
    Ginger Vieira July 8, 2010 at 9:19 am | | Reply

    Wow, thanks for such a great write-up about this issue. The Roche activity you helped organize was really eye-opening and educational on how just twisty our test strips really are.



  5. emericle
    emericle July 8, 2010 at 10:17 am | | Reply

    An even better, but potentially more costly option would be test strips that fit your use case. Offer a product for those who are more concerned with high precision at the low end of the BG spectrum, one for the high end of the spectrum and one with greater precision at the “normal” range, but loses accuracy as it reaches the extremes.

    This gives patients the flexibility to use strips to gain a better idea at all points.

  6. Stella'smom
    Stella'smom July 8, 2010 at 11:03 am | | Reply

    why can’t they make two kinds — one more accurate on the highs, one on the lows? That way the patient/consumer can pick? Because everyone’s diabetes is different and every pwd has a right to chose their best treatment.

  7. George
    George July 8, 2010 at 11:17 am | | Reply

    My feelings at first were the lows but when I realized (after some discussion) is that highs are where the long term damage is done. We need to get out of those highs as quickly as we can so knowing exactly where we are when we are in the 200′s and 300′s seems more of a concern.

    I mean, I would treat a 48 the same way I treat a 62. 15g of carbs then test. But I would treat 220 different than I treat a 160.

  8. joan
    joan July 8, 2010 at 12:38 pm | | Reply

    I am really glad this situation is being addressed.

    Recently before breakfast I tested at 235 (which didn’t make sense) so I tested again and it was 90!! Imagine what would have happened had I taken an insulin bolus for a 235 and my carbs. Definitely Urgent Care time. By the way, I did test two hours later to make sure the 90 was accurate.

    I have gotten to the point where each time I have a high, I test twice.

  9. Joseph
    Joseph July 8, 2010 at 10:33 pm | | Reply

    good to know that the error rate is minimal, because this way we can improve a lot, good blog ….

  10. Scott Strange
    Scott Strange July 9, 2010 at 6:30 am | | Reply

    emericle asked about 2 different types of strips. That is a good question, how would the accuracy, either high-end or low-end, be increased? Would it be thru strip technology, meter technology or both?

    If it is thru the meter, could it have different modes? High-mode and low-mode?

    How would increased accuracy at either end affect readings in the middle?

  11. mcityrk
    mcityrk July 10, 2010 at 3:26 am | | Reply

    This is an interesting discussion of measurement accuracy over full glucose range which has been going on in one for or another for at least the last 25 years. All of the systems ever developed and marketed have had to deal with the trade-offs between user convenience, speed of system response, accuracy and reproducibility over full glucose measurement range, and measurement cost as it is impossible to simultaneously optimize all 4 factors at the same time. My own experience was as a chemist helping to develop the Direct 30/30 meter [marketed through Eli Lilly from 1989-1991]. This was a meter based on an electrochemical sensor which was reusable over the course of weeks and even months. Good analytical performance with comparable accuracy over a wide measurement range [40 to 400 mg/dl] and way ahead of its time in cost per test for high-frequency users since it was reusable, but with a slower measurement time relative to today’s strips [30 vs 5 sec], requiring a warm-up of a few hours to allow the sensor membrane to stably hydrate, and needing daily user maintenance to keep the sensor membrane area properly hydrated with daily calibration rechecks to verify continuing accuracy. This led to minimal market acceptance as users demanded total freedom from maintenance [comparable to the convenience delivered by a strip meter] as well as measurement speed and reasonable accuracy. Since this was pre-DCCT times, high- frequency testing was minimally practiced and the potential testing cost advantage was not considered so important. [FYI- These principles carry over in large part to the way CGM sensors work today, except of course the patient interstitial fluid acts to keep the sensor membrane constantly hydrated in a more consistent environment so less frequent recalibration is usually needed to verify accuracy].

    But to some of the questions posed in this blog: Why the accuracy difference for sensor strips over different parts of the measurement spectrum, and how can two strips from the same packet show such large variability for essentially the same sample?

    As a start, for cost reasons, most strip developers have optimized/minimized the quantity of enzyme reagents [reactants and cofactors] necessary to allow adequate signal development in the devices measurement time window. This usually implies optimizing for 75-250 mg/dl as this is where most readings will fall. When glucose is below these levels there may be little sensor signal relative to system background signal and depending on measurement data handling algorithms a high percentage error can result. The faster the measurement time the higher the probability for this error since sensor signal is less fully developed and makes up an even smaller part of the overall signal than if the signal was allowed to develop longer. At much higher glucose levels, the possibility also exists that one of the reagents will be exhausted prior to completing the measurement timing cycle so observed change in signal level is not representative of sample and the data treatment algorithm will be tricked to introduce an unpredictable error. Additionally, small artifacts in sample introduction to the strip can cause the device to trigger measurement of starting and ending signal levels at the wrong times so that the signal change measured is not representative of the true sample glucose. Again, the shorter the measurement time the larger the error from sampling artifacts can be. This can cause strange outliers in either direction across all glucose ranges and probably explains the variability described by Joan in one of the blog posts for essentially identical samples on two separate strips. Like it or not, the possibility of user technique artifacts exists and can occasionally invalidate the accuracy of a strip measurement. Of course, a great deal of work goes into the strip development to minimize the possibility of this happening but technique sensitivity can never be completely eliminated. Additionally, since the measurement consumes the strip reagents it is impossible to quantify the cause of the problem later on so both developer and user blame each other for the failure [i.e. The never-ending argument: Was it just an incorrectly manufactured strip or poor user technique? No way to tell].

    As to the idea of multiple strips for different measurement ranges: certainly possible in principle but probably with insufficient market size to warrent the time, effort, and money needed for the development. We actually proposed a device to measure low glucose in pediatric patients 20 years ago but were told it was a trivial follow-up to previously developed technology and the market was too small to matter.

  12. Alice
    Alice July 18, 2010 at 8:16 am | | Reply

    I found diabetic test strips WAY below pharmacy prices ($15/box!)

    Hi all,
    Thought this could help someone…I did a Google search for “cheap diabetic test strips” and came across this site that led me to a fellow diabetic that had my Freestyle Litr strips (50 ct) for $15 a box (plus S/H), and they don’t expire until the end of next year! What a godsend!
    The site is , and they also have One Touch, Contour, etc. Thanks

  13. Mitch
    Mitch August 3, 2010 at 6:59 am | | Reply

    While accuracy is important, I suggest that it is a distraction from the discussion of COST.

    Manufacturers would love to have all of us arguing about which meter technology is the most accurate because we aren’t talking any longer about how each test strip costs more than $1 apiece.

    To put the issue of accuracy in context, spend a few test strip dollars by testing multiple fingers of each hand within a 30 second period — then ask yourself, “what’s the fuss about accuracy compared to cost?”

  14. jim snell
    jim snell March 11, 2013 at 9:42 am | | Reply

    Hey; as one whose readinsg go 40 to 100 points off due to what I am eating and the man made sugars in the stuff; I object to this cavalier attitude about accuracy.

    Accuracy that changes as I eat is crap and so are the strips that jump off.

    Yes in am all meters read well but eat and wait 2 hours and see where one is.

    This is not a discussion about accuracy but one of reliable consistent results. My liver does not play nice and shoots the non glucose D sugars into the main blood system for another pass thru the liver and past my fingertips to throw meters off scent that cannot meaure glucose d properly.

    A meter that works consistently but has some reading issues but are consistent, I can live with and compensate. Something that is bumping around 40 to 100 points off based on the food I eat and the man made sugars stuffed in the stuff is totally unpredictable.

    Please – lets have some rational discussion and get the slug strip technology out of the loop.

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