Yet another meter question

[georgepds]

Yes I know they are only 10% accurate.. but my question is why are they dead on with he test solution, but off with blood from the same drop

This morning I decided to test out my new one touch ultra (OTU). I set up both the new and old OTU, and drew blood from the same blood drop. One read 116, the other 133

OK, it could be a calibration problem, so I take the test solution and apply it to both new and old meter, and I get the exact same result (133)

Now that is way too close to be a statistical fluke (and I'm way too cheap to invest in more than 4 strips on the problem). So the question is: are test readings on test solution truly more accurate than test readings on blood.. if so why?

[fgummett]

Are they dead on with the test solution?

My current batch of Bayer Contour strips states on the bottle that anything between 5.9-8.2mmol/l (106-146mg/dl) is acceptable with the control

[MCS]

I found that the reli-on meter from wal-mart, the side kick is accurate.

What I do is look at the range of the test solution and determine the mid point, the meters I purchase are always with in 1-2 pts of that mark.

In order to duplicate this kind of accuracy with your blood, you must alliviate all possible false positives and or flase negatives. The sample size required for these strips is so small that any contamination of any size will throw off your readings. So what I am trying to say, wash your hands, rinse until they are squeaky, dry on a clean towel or napkin. Then try the readings with both meters. Use the same drop of blood, do not re-press your finger to get more. Hope this helps.

What I have found out after a high number is: why waste another strip, I know I will wash my hands and have to test again because I didn't believe the first reading I got.

[Granny Shanny]

Note the "clean towel/napkin" part. I've adopted this practice also . . . I don't even use a paper towel or tissue that's been exposed to the room air - I take a clean towel from the closet & use the inside of the folds. I don't use fabric softener sheets with laundry, so there's the least possible risk of contamination. No, I'm not this anal about anything else!

[Hammer]

George, if you look at the test solution, it has a range....like from 104 to 144. Since most meters can be off by 20%, that means that the test solution is probably around 124, so plus or minus 20% would be about 104 to 144.

Before I test, I wash my hands, then after drying them thoroughly, I wipe the finger with an alcohol soaked cotton ball. After allowing it to completely dry, I then test. I have never gotten a bad reading doing this.;)

[georgepds]

Ok, thanks

I'll try the super clean hands trick (with alcohol). I do wash before I test.. but only for the duration of happy B'day tune, and I use the towels hanging in the bath

That the solution came out identical, and the blood (from the same drop) came out different is the point that threw me for a loop.

I find it difficult to believe that a statistical quantity ( glucose dilution) can vary in a single drop of blood.

Next test is same drop of blood, same meter

I ordered a bunch of test strips so that I can work this out a bit better ( also to discover what my 2 hour post meal levels are.. right now I just have strips sufficient for morning/evening readings)