Most meters today indicate they take a very small sample of blood to test. My concern is the crazy results I have gotten from almost every brand of meter I have owned. For example, my fasting blood sugar was 135. I had a biscuit and gravy for breakfast. I did not get to test at the 2 hour mark, but before lunch it first tested at 108. No, I did not exercise at all. My most vigorous activity was to walk to the bathroom. Not trusting this result, I tested again getting about twice as big a blood drop and it was 135. To me this was much more realistic than 108.
As I said, this has not been the only time or brand of meter I have encountered results similar to this. I understand that no two drops of blood will test the same because the glucose in the blood stream is not consistent all over.
Just wondered if anyone else had encountered something like this.
Blood glucose tests even a short time apart can vary with any type of meter, but as far as I know, if you have enough blood for the meter to begin testing, more blood isn’t going to make any difference in the test results.
Try different meters. I’ve been using meters since 1992. Many different models. Some of the most accurate and repeateable results have come from my current meters, the Contour Next. If you were to get wildly different results a few moments apart, I’d have to say it was user error, as in this household, with two people, 4 Contour Nexts, accuracy/repeatability has been amazing and better than any other brands that we have tried. That says a lot. I’m sure there are other meters that can match that, but I must have somehow managed not to have tried it.
I would say that in nearly a year’s time, testing MORE than 12 times a day, I can recall getting no more than 3 weird results. Can’t say that about some of the other meters I’ve used. for example, Accucheck Compact and Compact Plus always read too high once the true bg reading starts to climb above roughly 150. In the critical low range they are as accurate as the Next and many of my other meters.
Don’t expect EXACT results if you test from two different drops of blood, even within a minute. For testing repeatability of results, use a huge drop and place part of that drop onto a couple of successive strips. Then you are going to get the most reliable indication of how consistent a meter will be, rather then testing with blood from different finger sticks.
I have had some wildly different results from various meters as well. Now that I’m using the Livongo InTouch meter, I spoke with a coach about this. He told me that they recommend the “second drop method” – do a finger stick, wipe away the first blood that appears and test the next drop. He said that the second drop is usually a better indication of the real BG. I’m not sure, but that’s what they recommended to me,
I understand what you are saying. I have tested meters using large drops of blood with several strips also. Every time I have gotten what I consider weird results there has been a vast difference between the amount of blood tested. Each time the larger drop always read higher.
Thas, that’s certainly something to think about. I have done a number of sticks where either my hands were cold or I did not stick in the right place and had to wipe away the blood and try again, but I’ve never deliberately done that. Definitely food for thought.
I’m not certain I have the % amount correct, but the standards are such that BG meters are allowed to be up to 20(?)% off in either direction from ones actual blood glucose level. (Someone please correct me if I’m wrong.) That variability can come into play when comparing BG readings on the same drop of blood with the same meter.
I get NO WHERE NEAR a 20% variation when using a quality meter. In the PAST, I’ve had meters that were quite variable, but recent meters I’ve owned do far better, and the king of them all is the Contour Next. It’s a shame I can’t see it in bright sunlight, so I take a different meter with me (Verio) when I’m out and about. It’s decently accurate too.
I consider a 20% variance to be totally unacceptable.
I think the concept of the +/- 20% margin of error is often not understood correctly due to lack of appropriate context…
That is the regulatory requirement that manufacturers are required to prove that they meet— it is not representative of the level of accuracy that we should actually expect to see. Someone with my goals of tight control would find a meter with +/- 20% completely useless… I can literally guess my bg closer than +/- 20%.
All that this means is that it’s the regulatory minimum they must document, not an actual statement of what we should expect… That seems to get lost in translation a lot.
That being said-- I agree it should be tighter. There’s interesting info included in the package with bg meters that shows some detailed info about their accuracy far more meaningful than the +/- 20% fda standard
Exactly. My problem is that a lot of insurance companies require you to use the meter they have a contract with or pay for your strips. I have a Medicare Advantage plan so cost is a factor. So far I’ve us to use 3 different meters just since I retired. I so would like to get to stick with just one meter.
This upset me so much I opted to pay for my own preferred strips out of pocket and take the ball completely out of their court-- luckily for me I like some of the inexpensive knes @Ila1
I have a slow internet connection so I can’t quickly pull up the standard. My memory tells me that for BGs above a certain hypo threshold, perhaps 70 mg/dl, +/- 20% from the actual blood glucose is considered acceptable. For the hypo range it is narrowed to +/- 20 mg/dl.
I believe a tighter standard is either proposed or recently adopted.
I agree. For those of us that use there numbers to dose insulin, a hormone capable of causing death directly or indirectly when combined with driving, for example, the accuracy and precision of these instruments needs to be better. Since T1Ds are such a small portion of all people that depend on these instruments, I fear that the business analysis interests leave T1Ds frightfully vulnerable to the acceptable accuracy standard.
Perhaps we need to press the device manufacturers to produce a better quality instrument at a higher price. In fact, it may be that the quality of the strips is the real challenge to increasing accuracy and precision.
I believe that all meters are essentially 100% accurate. They are just electrical meters, not a lot to be wrong about within the meter when you’re simply measuring the voltage and/ or electrical resistance created by a chemical reaction within the strip.
I believe variability in the strips themselves accounts for nearly all accuracy issues and fluctuations, as well as they have to be calibrated for a certain baseline which may well not match well with the actual users blood chemistry… Note that if you read all the fine print they specify the hematocrit and hemoglobin count that they are certified to meet the requirements within, etc
My only complaint of accuracy stems from variations with temperature of my strips… Cold strips = higher bg readings for some reason with mine… As I encounter major temperature variations from well below zero to well above 100f within a given hour in my line of work, this can be problematic for me and I have to keep my strips in a controlled climate.
I use Freestyle Lite meters that are rated highly and use very small drops of blood. It is my opinion that I get better results when I use slightly larger drops. If I use a tiny sample, the meter will work but give a result that is often lower than a larger drop. So if I can’t get a decent sample size, I keep poking until I do. In the winter when my hands are cold it is sometimes difficult to get a decent sample size.
The thing that astounds me, in addition to a standard like I wrote about above, the standard allows up to 5% of the test results to be complete outliers. So, you might stick your finger and get a 330 mg/dl when your sugar is really 100 mg/dl and that is completely allowable within the current standard. That is dangerous if you depend on that wacky number and go ahead and deliver a big correction.
I try to always take two BG tests if the first one differs a lot from my CGM. I think that most of us have quickly bolused for an outrageously high BG result and then tested again to find a more expected result. And oops, now you have a couple units on IOB for a normal BG…
I do the same, @Laddie. I’l sometimes I do three consecutive 'sticks if disagreement remains between those numbers, my CGM, and how I feel. I’ll even do a third fingerstick is the first two numbers are too far apart. (Cue insurers cringing!)
There was a time in my diabetic life, however, without a CGM, and I would depend on a single fingerstick while my physical awareness of hypos was blunted.
I have many mornings where I do “double tests” several times. At the same time I bolus and eat glucose tabs based on my CGM all night long. So on one hand I go crazy with questionable results and then on the other hand, there is no way I am getting out of bed to test, so the CGM is good enough. My system must be working because I am still alive!
i tried using the Verio and had the worst accuracy of all the meters i have ever used. i got continuously high BG readings and was over-bolusing every time i based my BG on the Verio reading. finally, i compared the Verio to three other meters, and could see how way off it was. also, it never jibed with my cgm readings. finally i switched to the One Touch Ultra 2 and have been having quite decent results as far as accuracy goes. unfortunately, it does take a bit more of blood than all the newer meters. fortunately, i am use to this.
however, i am on Medicare and they only pay for the One Touch meters and strips. but they do pay 100%. my endo is happy to give me (for free) any meter i want, but the problem is that Medicare won’t pay for my test strips.
