Test monitor accuracy?

[TerryinDorset]

Shock horror. I've been using a Accu-Chek Active monitor for 2 months & for the past 7 days got fasting values of 5.0 - 6.0 mmol. 2 hrs after lunch today I got 6.2. Two mins later I tried the AgaMatrix 'Jazz' that my diabetic nurse gave me recently & got 7.2mmol.
I'm confused now about which machine to use. After a few tests, it seems the AgaMatrix is giving numbers 1 higher than the Accu-Chek. I'd be interested in views about this anomaly. Which is the more accurate monitor?
By the way: I did a AgaMatrix Control Solution test which gave 7.2. I rang their customer care & was told this number means the Jazz is accurate.

 

[ally1]

I have 2 different monitors and they vary by 3

 

[TerryinDorset]

Wow!! Which one do you use?

 

[TorqPenderloin]

Every meter has a margin of error. I would personally consider a meter than is accurate to within 15% to be accurate and one within 10% to be extremely accurate.

Control solutions will help to calibrate a meter, but there will still be a margin of error. The only thing the control solution assists with is whether or not your meter reads high or low.

6.2 and 7.2 reads could mean your meters are accurate to within 7.5% or they may be off much more than that.

A few examples assuming your actual blood sugar was 6.0
Accurate to within 10%: 5.4-6.6 mmol/L range
15%: 5.1-6.9 mmol/L range
20%: 4.8-7.2 mmol/L range

Plus, you also have to factor in the fact that different samples of blood may yield different results even with a meter than is 100% accurate.

If I ever have an unusual reading, I'll test 3 times at once and average the three results together.

 

[TerryinDorset]

Hello. I did retest with both & the Agamatrix gave bigger differences than the Accu-Chek. I had a look on line for accuracy listings.
I found one that gave the Accu-Chek Active a 80% rating. I'm used to getting readings in the 5-6 range & was shocked at the raised A-Matrix readings.
Thanks.

 

[Gaz-M]

I would stick with 1 meter and go by that reading then you will know where you are at

 

[Prem51]

People on here have said they get different readings using the same meter on the same finger one test just after the first.
The meters aren't completely accurate, but they give you an idea of where you are. The HbA1c blood test which gives a reading of BS over the previous 12 weeks is the way to get an accurate result.

 

[TerryinDorset]

Good morning. This is the first time I've used these things and I assumed they would be accurate. I did think like most thing there would be a margin for error. It seems both give correct readings according to the bloke at AgaMatrix. I'm going to use the Accu-Chek until I've used all the strips up, having bought 100.
I have a HbA test in March so might not test so much until then. The picture I have so far tells me my BS is stable & what is expected. My dieting continues, so fingers crossed.
I might give the AgaMatrix back with the 50 strips.
Cheers.

 

[amgrundy]

Surprised at different readings on different meters, I have an Accu-chek.

 

[numan43]

my codefree consistently reads higher than optium neo

 

[TerryinDorset]

I bought a friend with type 2 a Codefree as his surgery hadn't given him a test meter. I don't think he uses it much though!

Info: I got these readings yesterday 2hr post meal - AccuC Active, 7pm 6,1, retest 7.30pm 7.1, & then7.0.
Agamatrix Jazz 7.8, then 7.30pm 9.1, 8.3. As the Jazz is giving more variable readings & seems less consistent I've decided to give it back to the diab. nurse & use the Active.
What concerns me is that I'm checking readings that vary so much again set numbers.
I have a HbA1 test in March & won't test so much until then....maybe every other day. The last HbA1 reading in Nov.'15 was 60 or 62. Thanks for all your inputs.

 

[Oldvatr]

my codefree consistently reads higher than optium neo

Ditto My SD says it is calibrated for Plasma blood, so will be calibrated to read 12% HIGHER than a meter calibrated for ;whole blood; such as the older NEO and Accuchecks. Also there may be up to 40% difference between the meters due to ISO accuracy requirements [i,e, first meter is allowed to be 20% high, and another meter could be 20% low and both would be considered to be 'within accuracy' and correct. So, if bgl is actually 20 mmol/l then you could experience an 8 mmol/L difference between two meters]

 

[catherinecherub]

There are some explanations in this article about the accuracy of our meters.

http://www.healthline.com/diabetesmine/why-meters-cant-tell-us-our-blood-sugar-levels#1

 

[Mep]

yeh I get different readings on different meters and different fingers as well. But they all tend to be anywhere from .5 to 3mmol difference. Like today I tested at 5.3 but was feeling like I was about to hypo... I think my meter is slightly out. I had dinner and bolus'd less than usual and was 5.8 when I tested 2 hours afterwards. So normally I'd be probably higher on more insulin. So what I'm saying here is I think my meter reading of 5.3 was wrong and I was lower (I can normally feel it). It also reminds me why my endo insists I have to be above 5 on my meter at all times... probably he also knows these meters aren't 100% accurate.

 

[Oldvatr]

There are some explanations in this article about the accuracy of our meters.

http://www.healthline.com/diabetesmine/why-meters-cant-tell-us-our-blood-sugar-levels#1

Sorry, think the reporter has got her whole blood and plasma terms mixed up.
I provide links to 2 papers that seem to be the other way round.

http://www.joslin.org/info/plasma_glucose_meters_and_whole_blood_meters.html
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903977/

The problem is the term plasma used for describing the interstitial fluid measured by the meter here is not the same as blood plasma as used in transfusions. I think it would have been simpler to use the terms venous and capilliary blood, which is what they used to be called Anyway, new meters will probably read some 11% or 12%.higher than the older meters.

 

[TerryinDorset]

Oldvatr.....that makes more sense so what does the Accuchek Active test for/with? I'm giving it capilliary blood............

 

[Kalisun1]

Hey can I ask a question in here. I had a meter test done last year to see if I had diabetes. Flash forward now and I'm having some symptoms. Tomorrow I go to take another test. Should I take the other test with it or is a the meter test good enough?

 

[Oldvatr]

Oldvatr.....that makes more sense so what does the Accuchek Active test for/with? I'm giving it capilliary blood............

If it is not stated in the instruction leaflet, then you will need to contact the manufacturer directly. Currently there is only one site I have found that has published a table of meter models that have now converted to the new 'plasma' calibration, but from what I could see it did not cover models available in UK.

I did find this for you, but it may not apply to your meter.
01/06/2010

Accu‑Chek® test strips have changed to plasma calibration
Blood glucose meter systems can be calibrated for whole blood or for plasma, depending on the supplier. Accu-Chek blood glucose meter systems have until recently displayed blood glucose levels based on whole blood.

Throughout 2009 we gradually changed the Accu-Chek strips to plasma calibration to bring ourselves into line with the international standard. Accu-Chek Mobile was launched in 2010 with plasma calibration.

@Administrator We have it in writing now I was not spouting BS.!

 

[Oldvatr]

Hey can I ask a question in here. I had a meter test done last year to see if I had diabetes. Flash forward now and I'm having some symptoms. Tomorrow I go to take another test. Should I take the other test with it or is a the meter test good enough?

You need to ask the ones performing the test. As a general observation, GP's will use venous blood tests rather than a portable meter to base a diagnosis on,, and generally will do at least two different types of test using a laboratory to establish traceable results. A home meter is not a diagnostic tool.

A GP may use a practice owned meter for an initial looksee but will not rely on it and will certainly follow up with lab tests if it indicates a possible problem. This was how I started, but it was the HbA1c that clinched it.

 

[Kalisun1]

You need to ask the ones performing the test. As a general observation, GP's will use venous blood tests rather than a portable meter to base a diagnosis on,, and generally will do at least two different types of test using a laboratory to establish traceable results. A home meter is not a diagnostic tool.

A GP may use a practice owned meter for an initial looksee but will not rely on it and will certainly follow up with lab tests if it indicates a possible problem. This was how I started, but it was the HbA1c that clinched it.

Thank you. You did the finger test then the hba1c? I'm thinking of doing the finger test then giving blood for them to test more. I'm sorry if my question sound ridiculous but I'm still somewhat new to this.