Readings between 2 different meters are of as much as 20

[erif902]

First off, Hello to all (first post/newly diagnosed with t2 )
Does anyone have experience with relion premier blu meter . i have two meters (fora g20/relion premier blu) one as a backup. tried last month to use relion after not planning ahead and running out of test strips . went to walmart and bought relion meter . but decided to try against each other and found readings to be as much 21 points from each other . nurse said meters are all calibrated to differently and not to a standard.
my note to was , Ok but one reading is good and the other has deadly consequences , and outcome of readings also fortell what to eat and what not too.

[Eric]

Hi @erif902! Welcome to FUD.

As far as being precise, a lot of meters can be kind of dicey like that. I tried that meter you are talking about and was not impressed.

There is really no argument about which meter is the best. It’s pretty much agreed on here that this is the meter to get. The strips are not too expensive so you can use this without any prescription. Probably just as cheap as what people pay for prescription strips.

Check out this thread on FUD:

Best meter on the planet

I don’t know what other meter is going to give you such tight grouping. You can use standard deviation or any other measure of dispersion you want. Nothing touches this meter. For anyone looking for a meter, or asking which meter is the best, Contour Next One is your answer. https://www.contournext.com/products/contour-next-one/ Thanks and have a good day. [image]

[Chris]

@erif902 sadly your experience isn’t unusual. Some meters will read a 20 point difference with sequential strips from the same blood drop. As @Eric mentions, we follow all the studies of accuracy closely. Your Fora g20 is not one I have heard mentioned or seen measured in the head to head studies that researchers have done. Here is one of the studies that was published from 2017. You will notice that there is variability even within brands. It seems that some strip designs and manufacturing plants produce higher quality products.

Meter Accuracy - Did your meter pass the "test"?

Link to the data: https://www.diabetestechnology.org/surveillance.shtml

[Eric]

Look at those people spending thousands of dollars to come up with the same result that I got in my kitchen.

[jim26]

I use Accu Check Guide meter and find it provides consistent results and find it also matches my lab draw within a couple points. Very pleased with it. I have used Contour and agree with @Eric it is a great meter.

Avoid One Touch at all costs. It is a random number generator.

[erif902]

Thanks to everyone who responded to my question . now i have one other reading through manual. should I get the control solution it says to do it everytime you start new test strips among other things

[bkh]

I never use control solution. It really doesn’t show anything about accuracy, it basically just tests the meter for “completely broken” vs “detects glucose.”

[CatLady]

@bkh

never use control solution

Me, neither.

[Chris]

Can confirm, son has been a diabetic for 6 years, never used control solution (also couldn’t tell me what it is for) and is still alive, and thriving. /s

[Mariethm]

Almost 6 years for me as well, and I still have no clue what this “control solution” is. Meter handbooks talk about it, but I figure if its that important, drug companies would have ads for it all over my fb feed.

[TomH]

@psfud123 While I like the idea of testing BG just before a lab test, my recent experience at surgical clinic causes me pause. Their test of my BG before a procedures was way off of both my G6 and Contour Next One. The hospital test machine (red, 3”x3’x8”, I didn’t check the make/model) was significantly high (out of range), while the G6 and Contour were within 8 pts of each other (middle range). I told the surgical center we were going with my readings, not thier’s (they agreed and decided their machine needed checking). This wasn’t a “lab” test per se, but Lord knows how long they’d been using their machine. I’ll have to look at what labs use and how often they get tested against a known sample (control fluid?).

Tom
“A man with one watch knows what time it is…a man with two watches is never sure!”

[bkh]

@psfud123

If you read the directions that is included with every single one of them they tell you not to make management decisions based upon their values but to use the fingers stick meter.

You mean like this? (https://www.dexcom.com/)

"The Dexcom G6 is FDA-permitted to make diabetes treatment decisions without confirmatory fingersticks or calibration.*

*Fingersticks required for diabetes treatment decisions if symptoms or expectations do not match readings."

Or this? (Continuous Glucose Monitoring (CGM) Systems | FreeStyle Libre US)

"With the FreeStyle Libre 2 system, you can check your glucose with a painless*1,2 scan instead of fingersticks.†

† Fingersticks are required if your glucose alarms and readings do not match symptoms or when you see Check Blood Glucose symbol during the first 12 hours."

[Jan]

I use Accu Check meters, and I have used ReliOn meter from Walmart upon recommendation from OBGYN who’s wife had gestational diabetes, and because the test strips are so cheap. But I found it to be wildly inconsistent, so it’s a back, back, back-up now.

I’ve been Type 1 for 43 years and I’ve never used the control solution.

You have to realize that even the best meter is an estimate of your actual BG. I can find a difference of 10 to 20% between sequential BG values from different fingers!! Anyone else experience this??

Anyway, even with the advanced technology that we have available, these are still estimates of actual BG. What we want is the best estimate we can get.

[Chris]

@TomH, when people are talking about readings from a clinic, they are referring to lab values which @psfud123 calls out well. If it isn’t being delivered by an actual lab, then their readings are no better than yours. Portable machines just aren’t handled very well in practice, whether they are in a medical facility or not. It is the actual lab values you want to compare against from a blood draw.

[Sam]

Control solution is a total waste of time.

[jbowler]

@psfud123

The G6 doesn’t measure blood glucose at all. It measures interstitial glucose levels and makes an estimate based upon a large number of samples in a lab. The standards for CGMs are plus or minus 20% of a laboratory value within the control range and plus or minus 20 points outside of it, all these being in mg/dl.

I just found a PubMed paper documenting the actual performance of the G6 (this is cross posted in the recent thread about the G7, which seems to be considerably more accurate):

Accuracy of Dexcom G6 Continuous Glucose Monitoring in Non–Critically Ill...

So, in fact, comparing the G6 using test strip standards the G6 is worse than +/-30%,+/-30mg/dL. The test strip standards are based on ranges such that 95% or better of the tests are within range - the G6 only achieves 93.6% at the +/-30 range.

The G7 information suggests that the test being used for CGMs is not one about the absolute proportion of tests that are in a particular range (as for test strips) but the average (mean) error from the real BG [MARD]. That makes sense to me because CGMs squirt out readings continuously, test strips produce single results which we rely on without, normally, re-testing to make sure.

[bkh]

@jbowler

The G7 information suggests that the test being used for CGMs is not one about the absolute proportion of tests that are in a particular range (as for test strips) but the average (mean) error from the real BG [MARD].

And also, the nature of the error. (“Clarke Error Grid”) Basically, if the error won’t lead you into danger, that is more easily forgiven. Consider which is worse: an instrument that says you’re at 85 when you are actually at 45, or an instrument that says you are at 45 when you actually are at 85. In the first case, if you believe the instrument you could, for instance, crash your car because you are severely hypo. In the second instance you might eat some glucose and refrain from driving for a while, and inadvertently drive your BG up 40 points to land at 125.

[jbowler]

@bkh

And also, the nature of the error. (“Clarke Error Grid”)

That’s something that has always concerned me about the complaints of test strip inaccuracy and, maybe, the ISO protocol for testing them. It is appropriate to include a high proportion of low BG samples in the test but the value of accuracy on high BG numbers is, for me, slim; I’m taking action at 200mg/dL, so a 20% error is still 160mg/dL (well, slightly more) but that’s fine, I’ve got lots of space, lots of time, at high BG to react.

So that leads me to understand why a manufacturer might introduce a systematic error, consistently reading low, to handle lots of test strips which read high. This produces a higher MARD; a significantly higher MARD because all the readings are low, but maybe it saves lives.