New Meter - Different Results

[Dougie22]

I have been using my Accu Chek Compact since diagnosis (a couple of years ago) with few problems. I got a bit lazy as nothing was changing very much and had a break from June till late November where I did no testing at all. Since mid November, my readings have been higher than they were up until June (fasting around 11 or so). While it is true to say that my control has not been good, it has been no worse than usual during this period. So started taking regular readings and they have stayed relatively high, even when I've been behaving myself. I decided I'd have to make a more concerted effort after Christmas and get back to multiple daily tests. 51 strips for this meter are over £20 retail, slightly less on ebay, where I buy mine.

So in preparation for a renewed effort, I've purchased a Code Free meter through Amazon and have started trying it out, with a view to switching over to cheaper strips (50 for £6.99).

To my surprise, readings on the Code Free are about 2mmol/l less than on the Accu Chek from the same drop of blood. This seems significant to me as it makes the difference between a fasting reading of 11.2 and 9.2 (roughly 20%). Even taking the attitude that we're looking at movement from one day to another, this seems a significant difference.

I am now left wondering which one is correct.

I am inclined to believe the Code Free readings as:
- My symptoms haven't changed. I feel the same as I did in June
- My Accu Chek readings went up quite a bit (I did a calibration check with the liquid at the time, but it was just out of date)
- I was buying strips on the internet with the inherent risks that implies (all well within date)
- The Code Free is new with strips supplied and from a reliable source
- The Code Free results are more pleasing ;-)

I could get more calibration fluid and a new set of strips from Boots and might do this but it's a faff.

I will be going for HbA1c in January/February so that will authoritively let me know whether I've stayed the same or got worse during the period.

In the meantime, which figures should I believe?

(moved from another section of the forum)

 

[Yorksman]

Other posters often record that the Codefree is a point or two higher than the accuchek so your finding that it is less is new. In truth, neither is probably accurate as the requirement is plus or minus 10% of the true value for 95% of the readings. In other words, 1 reading in 20 can be wildly out and for meters, 9, 10 and 11 are all valid if 10 would be the true value.

There is little point in making these things very accurate as you will have a variation from finger to finger because of the way blood circulates and secondly, because you are using capillary blood, as opposed to venous blood, it has other fluids mixed in so it's not the best sample anyway.

What is important is that you compare readings from the same meter and your own technique of getting a sample. It is how this moves up or goes down that is important.