BG numbers using PDM vs other meters?

We have found that the numbers using the build in reader on the PDM have been significantly higher than the meter that we've been using since Emilie was diagnosed (OneTouch Ultra2). We like the fact that the Freestyle strips take a smaller sample, and allow you to add blood to it if you didn't get enough, but I'm worried about the numbers that we're getting. They seem to be about 40 points higher than the OneTouch.

The sales rep for the Omnipod of course sent us some information about how the FreeStyle is more accurate than the OneTouch, but I'm still nervous about making the change.

We are going to talk to the endocrinologist too, but I wanted to see if anyone else was seeing something similar.



CJ, I agree with you that meters will vary a bit from brand to brand, but 40 mg/dl seems a bit high. I have several meters and checked out the variation when I went on OmniPod. I did not see a significant difference myself, so I just use the pdm and Freestyle strips. You may also notice a difference in reading if you use another finger/location for the comparison. I think you are doing the right thing and checking with your endo. If in doubt, too much info is good. Hank

Yea, I'm going to start doing some more comparison's to see if it's consistant. The few times that I checked, I just made sure that there was enough of a sample to use both meters on the same sample. Do you think that's a good way to test, or would using two different sites be more accurate?

I read something today about how having something on your own hands while handling the test strips could also affect the readings. That makes sense now that I've read it, but I've never given it any thought! I'm always focused on cleaning the site that the blood is coming from, and not so much on my own hands!

I agree that the PDM meter reads higher, I found my A1C went up and could not figure out why until I read some posts and figured it out after I started using the new strips. I usually account for about 20 plus add'l points. I wish it wasn't the case but it is and since I don't want to carry an extra meter and such I just deal with it knowing that it is higher. I've since adjusted for it by just know that my numbers are higher, so I will adjust or not adjust based on knowing that. I'm hoping that this get this fixed or at least improved so that will be able to once again rely on the number being accurate. I would encourage you to keep track or montior from time to time and then use that info. to determine what your results are. Good Luck~Schmutz

I used to use the OneTouch Ultra Mini before I got my OmniPod pump in October 2011. I've compared the two of them together and I don't have that high of a difference between the two. Sounds like there's a possibility something is wrong with one of them. Now the sales reps are always going to say that one meter is more accurate than the other. I agree about asking the endocrinologist.

I recommend that you test your meters with control solution.

If your PDM reads higher, you should get a lower A1C, not higher, using it as glucometer.
You aim at 120, if your PDM reads +20 you are targeting a lower BG, the "old" 100.

I would question OneTouch Ultra2: were its readings consistent with your A1C ?

Our diabetes educators have recommended against control solutions, but not because they are not beneficial, but because the children (these educators are at Lucile Packard Children's Hospital), but because the children can get their hands on that control solution and use it to "fake" their numbers. We are not concerned with this because our daughter is 2, so she'd be more likely to drink it! :)

In all seriousness, the OmniPod was the one that we were sent home from the hospital with when she was diagnosed. We did plenty of checks with it while at the hospital, so we know it's at least close to what their BG testers were showing.


A while ago I did extensive tests and reported them here: A1C Surprise

My experience suggests that, of all the meters I've tried (Abbott (Freesytle), Bayer (Contour), Roche (AccuChek), Agamatrix (WaveSense)) they are all consistent when my blood glucose is in the range 80-160. Once it gets outside this range all bets are off.

Agamatrix fails, terminally, when presented with blood from cold hands; I abandoned it, it simply didn't work in winter.

Dexcom (CGM) was way out most of the time; it was only good for trends. I sent it back and demanded my money back.

I only really care in the range where the meters I've used are accurate - 80-160. If I'm above 160 mg/dl I'm high and it really doesn't matter how high because I won't be rational until I'm approaching 160 again. When my BS approaches 250 I will do several readings in a row using the same meter (at present a Bayer Contour USB). When I do this I consistently see massive variations between the readings.

I'm guessing that, since you are seeing 40mg/dl differences, your figures are likely to be over 140 a lot of the time. If so I wouldn't worry; the treatment is pretty much the same. You have to be careful not to OD on a correction so if you are correcting from a high reading it can get very difficult.

The correction itself often produces feelings of a *low* blood sugar even though the actual blood sugar is still high; I will get cranky if my blood sugar is falling rapidly, just as though I had a low blood sugar. Still, high is high; the best solution is a gradual return to normal.

John Bowler jbowler at

I think your original intuitions are correct; they mean Emilie's hands, not yours.

That advice is aimed at people who bake (or, maybe, eat donuts) and then do a blood test on *themselves*; the carbs on their hands from the flour and sugar dissolve in the blood sample and give a miraculously high reading.

John Bowler

I don't believe any of the meters calculate the average over time; the "average" they give is an average reading, which is basically meaningless. That number can't be compared with the corresponding HbA1c average blood glucose number.

John Bowler

I have suspected the same...the butterfly test strips in the oPod are reflecting lower numbers than the One Touch. I don't want to wait for my next A1c results to be proven correct. I will continue to use the Freestyle strips but I will use the results accordingly.

Fascinating...but not in a good way...
I saw a consistent bias on the low side with the new strips in the Omnipod and ended up using a trick from Helmut to get it to read like my old Freestyle meter.

Yet others on here say they see a bias to the high side ?

Randomly distributed differences of 20% must be discounted as the meters (of all brands) are not that accurate...but a consistent bias of even a small amount will lead to the surprise of the kind Helmut saw.

I just read through that thread. I am going to try that trick. Thanks everyone. BTW, the reason I switched back to Freestyle was that my endo requested it. His office even called the pharmacy to change my scrip. My insurance doesn't cover the Freestyle to the same degree, so I am paying more for less accuracy. I will bring this up at my appt later this month.