When you are a person living with diabetes, testing your blood glucose (BG) level is a vital part of each day. So it’s safe to say that the glucose meters we use to do those tests are important as well. We rely on these meters to give us information that is needed to properly calculate insulin doses. But what happens if those meters aren’t working properly or give results that aren’t quite accurate? In recent weeks, there were a few instances where I tested my BG to get a result that was way off to the reading that my Dexcom CGM showed. My first thought was that the CGM was incorrect, being that it is not a faultless means of glucose measurement. But it made me wonder so I did a second BG test. And the second result was way more in line to the Dexcom. Which made me wonder even more. So I did a third BG test. And that result would confirm that the first reading from my own blood test was incorrect. One example from last week – my first test resulted in a 91 mg/dl. My Dexcom said 180-something. Second and third tests resulted in 191 and 180-something mg/dl. That’s about a 100 mg/dl difference! If I had calculated my bolus based on the first reading, I would have vastly underestimated the insulin that I needed to cover my food and correct the high. I called the meter company and had them replace the meter for a new one. I’ve also gone back to the good old days of wiping my finger with an alcohol swab before each test. When testing 10 – 12 times a day, how convenient is that? Not very but I’m going to try and do everything I can to limit the chances of having elements affect the readings. I know Crystal had blogged about some meter concerns a while back and just today Kerri tweeted about having some inconsistent BG results from her meter too. So just how reliable are these “machines” we use? I know there is a margin of error in the readings they produce and they aren’t perfect … nothing is perfect. But our health depends on it. Ultimately, our lives depend on it.
I hate thinking my meter is wrong. Then again, I hate thinking I am wrong but I can’t go by what I “feel” so I test.
We rely on these readings to administer the correct amount of insulin in order to manage our Diabetes. How can these companies have such a wide control range, of which all levels of the medical community know of, and be expected to be in range ourselves? If the meter is not accurate, how can we be?
I hope the recent announcement I saw about the FDA holding hearings will push companies to tighten their control ranges and regard us as humans for a change and not focus on profit. (http://www.journalofdst.org/VOL-4-2-LTE-PINKOS.pdf)
I am interested in attending the FDA meeting. I have been looking into it and it is such a vital part of our health. I still would never trust the accuracy of the CGMs. Maybe in a couple of years or a couple of upgrades. It’s great they show trends, let’s just hope they will show real numbers some day soon.
It’s sad! That’s pretty much all I have to say on the issue. Hopefully the FDA will be able to do something about the inaccuracy (sp) of glucose meters. Great Post!
Now I am curious! I want to do an experiment and test without swabbing and then swab and test immediately to see if there’s a difference in the results.
Good blog – I do hope they can improve the accuracy. I know my meter says it can have a 10% variance.
Aghh yes. That’s the kind of thing that I can’t let myself think about for too long or I go crazy! Especially in winter when I tend to use more hand lotion and I try to remember all the tiny things that could get my meter way off besides just its own inaccuracies… Good to know about the FDA hearing – I will definitely keep a look out for that.
Oh my goodness! I feel rather stupid right now because I am always inclined to believe the meter over CGM!! Egad! And lord knows having a meter result and a CGM reading, you wouldn’t think you would need multiple meter results to get a sense of what your BG is. Thanks for posting this – it gives me a new perspective.
PS: You DID take a pic of that 100! Want to post it? http://www.flickr.com/groups/inthebgzone/
Which meter did you use? The Jazz or the Compact Plus? I’ve really had no problems with my Jazz meter, and I really believe it’s very accurate so I hope it’s not that one. I hope the new one works for you.
In the last year or so (thanks to the DOC) I’ve been more careful about washing my hands before testing, but I don’t really want to use a swab.
Bernard – I usually use the One Touch Ultralink that goes with the pump. I did use the Jazz for a short time when I got the meter + strips for free at an ADA Expo (the picture is a little old).
I also usually do the alcohol swab before testing but still found inconsistencies with the dexcom. It’s all too frustrating.