Inaccurate home test meters?

[juliekem]

Hello everyone
I have 2 different test meters and test strips, an Aviva and Code Free.
Thais morning I took my bg usinf the Aviva meter and it was 7.8 woooh very pleased as I have been only down to 20g carb per day since Monday! Something prompted me to repeat the reading using my Code Free meter - reading 8.9!
I immediately repeated the two readings (btw I used the same drop of blood each time for both meters) this time Aviva 8.0 and code Free 9.1. I grumbled to my other half a bit then took readings again - Aviva 8.1, Code Free 9.2.
OK I get that my bg is rising as I get up and move about but how on earth can I establish which meter is giving accurate readings? Ther local pharmacy will repeat a test but I don't know how old their meter is, it is only a "home test" one like the two I have. Can these things be calibrated?
Cheers
Julie
p.s. Before someone asks, I ran out of Code Free test strips last holiday so had to but some Aviva ones for my previous meter this is why I have 2 meters.

 

[tim2000s]

All meters are subject to a 15% tolerance, which means that both are likely to be correct as at the first reading, the range of possibilities for the Aviva is 6.7-8.9 and the Code Free is 7.6-10.2. Based on the overlap, of the two, it would suggest that your bg level was somewhere between 7.6 and 8.9. I would tend towards the Accu-check being closer to the "truth" based on "accuracy" tests I've seen, but as you see, neither is necessarily spot on!

There are test solutions of a specific glucose level that can be obtained from the vendor to calibrate your readings, but it's quite rare for there to be a big difference.

 

[AndBreathe]

I'd agree with almost everything Tim says, although I would pitch in that if you Google enough, you will find accuracy studies where the Codefree performs extremely well, and better than many of the big name manufacturers, whose strips are much more expensive if you are self funding.

The best plan is to choose which meter you're going to use, and stick with it. It makes all manner of sense to have a spare meter; especially one you can buy strips for "on the high street", as opposed to the Codefree's limited distributor network.

Based on bang for my personal buck, I use the Codefree routinely. At the rate the strips come in at, with the bulk buying discounts, I can test almost at will, as opposed to constantly balancing data against the costs of strips. After a time, I almost know where my bloods are likely to be in a given scenario, or after eating certain things, but testing keeps me on the straight and narrow.

Good luck with it all, @juliekem .

 

[juliekem]

Well I am horrified.
How on earth do I know what is happening if the test meters are so inaccurate? 8.9 is bad news but 7.8 is good news for me. The other fact is that the Code Free meter was within 0.1 of a test done at my local pharmacy although I agree that there are online articles that support the Aviva. I have sent off for Aviva test substance to check that meter and e-mailed the Code Free people so I can find out how to check that one. I really need to know what my bg is doing otherwise there is no real point in checking. Sticking to one meter will mean that I can do comparisons easily but if it isn't very accurate it is not much use.
Could this be why GPs suggest not testing very often for us type 2s??

 

[tim2000s]

Well I am horrified.
How on earth do I know what is happening if the test meters are so inaccurate? 8.9 is bad news but 7.8 is good news for me. The other fact is that the Code Free meter was within 0.1 of a test done at my local pharmacy although I agree that there are online articles that support the Aviva. I have sent off for Aviva test substance to check that meter and e-mailed the Code Free people so I can find out how to check that one. I really need to know what my bg is doing otherwise there is no real point in checking. Sticking to one meter will mean that I can do comparisons easily but if it isn't very accurate it is not much use.
Could this be why GPs suggest not testing very often for us type 2s??

If I'm honest, neither is good and your number should be in the 4-7 range, and as a T1, I wouldn't be happy around 7.8. The reality is that it doesn't matter too much and the 15% variance follows a bell curve and the 15% variance will be something like the 95th percentile. By the way, the pharmacy tests are no better than the meters you buy for home testing.

No this isn't why they don't recommend testing for t2s, that's purely a cost based thing. Accuracy is relative. Your finger stick blood will not contain the same amount of glucose as your veinous blood, which is different from your arterial blood. That in your hepatic portal vein is different from that in your aorta. Blood in one finger will give you a different finger prick result from blood in another finger.

If you take this into account, then you begin to realise you have to live with good enough, rather than thinking it's possible to deal with absolutes.

 

[AndBreathe]

Well I am horrified.
How on earth do I know what is happening if the test meters are so inaccurate? 8.9 is bad news but 7.8 is good news for me. The other fact is that the Code Free meter was within 0.1 of a test done at my local pharmacy although I agree that there are online articles that support the Aviva. I have sent off for Aviva test substance to check that meter and e-mailed the Code Free people so I can find out how to check that one. I really need to know what my bg is doing otherwise there is no real point in checking. Sticking to one meter will mean that I can do comparisons easily but if it isn't very accurate it is not much use.
Could this be why GPs suggest not testing very often for us type 2s??

Whilst I can appreciate your discomfiture, I would ask you to just breathe and take a little while to decide on your action plan. I think most of us have had those, "what the heck is going on here" moments at some stage.

I appreciate you are trying hard to control your condition and know that testing is an important tool in achieving that. I have absolutely no arguments there, or with you in general. However, the reality is that all meters show variances. Indeed, if you repeated your test, say, three times within 5 minutes, using the same meter (different droplets of blood and probably fingers), you are likely to experience a variation there too. For we T2s, who are either not taking any medication, or whose medication is unlikely to produce a hypoglycaemic event, the really important things for us are trends and ranges.

I have fairly tight ranges that my bloods tent to run in at various times of the day, and I tend to look for an upwards creep in the trend. When I was trying to achieve control, I was clearly looking for a downwards trend. As you may already appreciate, you could o pretty much the same things, and eat the same foods for a few days on the trot, and yet return slightly different scores for each day. Stress, sleep (or lack of it), illness and so many other things can impact on our scores.

If your Codefree reading and that done at the local pharmacy were close, then I'd take heart, and crack on with that.

It is my belief that the real reason T2s are not encouraged to test is financial. The sheer number of T2, multiplied by the costs of strips would be huge. Sadly, not all T2s are as motivated as many who find their ways here, and they pay lip service to the advice they are given, and wait for the medication to work it's magic. To make a real difference with T2, I think we'd agree that just isn't enough.

I do also think the secondary reasoning for not supporting testing for T2s is the initial support that would be required, so that the testing done would actually be understood and used to make changes, rather than just an exercise, like taking a tablet.

Please don't think this is any kind of telling off. It isn't, but the detail of this confounded disease, the management of it and the tools we have at our disposal can be bewildering at times; and frustrating as heck!

Stick with it. You'll get there.

 

[catherinecherub]

This article explains why meters cannot tell us our blood sugar levels and how they differ.

http://www.healthline.com/diabetesmine/why-meters-cant-tell-us-our-blood-sugar-levels#2

 

[juliekem]

"I'm honest, neither is good and your number should be in the 4-7 range,"
Thanx but I know - it is just that the 7.8 was a really good reading for me! Since last November (when my Hba1c was so good that my GP halved my dose of metformin and was talking about me coming off meds altogether) I have been struggling. Whether it was the 2 month bout of 'Flu I had after Christmas or the halving of the Metformin dose I don't know but my blood readings have soared thisd year and despite doing what I did last year I have been unable to get them down to the same levels, hence I have bitten the bullet and decided to go down to 20g carb a day (which I HATE btw.)
Last year I was able to eat about 50g carb a day and my bgs were really good (tho not quite non diabetic levels.) I could eat the little Fin Crisp sourdough crackers for example and even "cheat" a little occasionally. Not so this year. I eat one teaspoon of my h/m gooseberry jam the other day and threw a reading of 15!!! I have even been intermittent fasting but to no avail.

 

[Sirmione]

I currently have 5 meters:
My SD CodeFree gives readings which are quite similar to my Bayer Contour Next.
My two Freestyle Lite meters both give generally similar but slightly lower readings compared the Bayer or the SD
My my Nipro TRUEresult Twist gives noticeably the lowest readings.

The FreeStyles are probably the most accurate, and have a real quality feel about it.
The Bayer Contour Next is really nice meter very easy to set up and has great computer software.
The NipPro is a potentially good simple small meter but I don't like the unique cap mounted design feature and I don't trust the readings.
The SD has a big advantage in low running costs, but the computer software takes a bit of getting used to.

 

[catherinecherub]

Hi @juliekem,

The BP meds and the Simvastatin for cholesterol that you have been prescribed all have the potential to raise your blood sugars. Have any of these been added since your blood sugars have risen?

Might be worth asking for a medication review.

 

[juliekem]

No, apart from lowering the Metformin no new meds. I have also discontinued the simvastatin and Bendro- wotsit due to side effects (just updated my profile.) The other change is that due to ill effects for my other half, we have discontinued workouts at the gymn (until his AF is properly under control.) I garden (including digging etc) and walk the dogs still.