Unexpected HbA1c result

That should be a simple thing to get. The test is inexpensive and is certainly valid for anyone with diabetes, so it should be easy to get it done. And depending on what other tests they are doing at the same time, you may not even need to have a separate vial of blood taken out. They can probably do it from the same sample, which is nice.

It depends on the meter you are using. Some are really good, and some are horrible.

Get the Contour Next or Contour Next One. The strips are inexpensive and it is the most accurate meter there is.


Good to know. I’ll make a note to ask.

I’ve got two AccuChek Instant meters and insurance covers the test strips completely. How can I find the accuracy of this model?

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There are studies that do comparisons. But the problem is that we don’t really know all about how they’ve done it, and all the real-world scenarios.

Gary Schiener has a study. But it’s many years old and I’m not sure it includes your meter.

But the best thing would be to create a post and ask FUD members about their experience.

From me, Contour Next One is the best.


My personal test method is testing multiple samples with the meter and how close the readings are to each other. In my mind, the key is consistency in results.

OneTouch was a random number generator. My experience with accu check is they are very consistent. I’ve have used them for years.


Buy the HbA1c test strips/meters from Walgreens and use them. I was staring at mine today and thinking “must do that”.

TIR stats from a CGM are complete garbage. Obviously Dexcom paid a lot of money. Systemic errors of +/-20mg/dL (far less than those I have experienced) reduce a range of 70-180 to one of 90-160. The systemic errors I have seen - off by 40mg/dL, reduce 70-180 to 110-140. Complete, utter, garbage.

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What a curious assertion. I would argue that if a clinician receives a CGM-based 90-day AGP report showing time in range of 40%, that’s an excellent reason to investigate the graphs to find therapy changes, whereas if the AGP report shows TIR of 85%, in the absence of alarming lab results or patient concerns, it is fully reasonable to think that the treatment is in good shape. Hardly “Complete, utter, garbage.”


I agree with @jbowler on this one. TIR is only good if the data being collected is accurate. For Liam, nearly 75% of the time his CGM that’s reading as either GOING LOW, or IS LOW, is just wrong…confirmed by multiple finger sticks all the way down the fall. So, TIR fits into the concept of “crap in, crap out”. If you are lucky enough to have tech that reads your BGs accurately and correctly most of the time, TIR means a lot; otherwise, as @jbowler said, and I agree with, it’s complete and utter garbage.

CGM is good for us ONLY for the trending info it provides, nothing else. We never treat based on those numbers…that’s how little we trust it. We always do finger sticks before treating any suspected (according to the CGM) “low” or “high”.


I think we should be able to enter finger stick readings in the Dexcom app for these false lows and they should override the Dexcom data. I get these sudden drops from 90 to 100mg/dl 3 5 minute readings to a low or ultra low. Sometimes these events cause a loss of data for 30 to 40 minutes but not always.


@Finn I have to wonder – could your lab’s a1c result be off? Their equipment mis-calibrated; your results mixed with someone else’s; your results incorrectly entered (perhaps you’re really at 5.7 rather than 6.7?)?? It doesn’t seem like with everything you’re doing your a1c would have gone that much higher over the past few months. If you are able to source a home a1c kit (you’re in Germany, right?) or have the lab draw another one, it would be interesting to see what a second test would show. Either way, it doesn’t seem like there’s much you should be doing differently!

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I had those same thoughts, @JessicaD, although I’m not sure if they’re a bit too optimistic.

I don’t think I’ll bother with a home HbA1c test. I’m not sure how accurate they are and they don’t seem easy to find here in Germany. I’m not sweating over 6.7, it was just a surprise.

I’ve got another endo application in February and will probably have an appointment with my GP before the holidays (my GP usually likes to run a test if there’s a gap between my endo appointments).

I’ll wait see what my next HbA1c results come back as. Hopefully the results are more in line with what I expect.

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I think this is a very individual thing. I spot-check with a fingerstick once every couple of days and, except in the first one or two days of a sensor, my results are close enough for my CGM to be considered accurate, and I am very comfortable bolusing off my Dexcom number.

Meanwhile, my estimated A1c has always, for as long as I’ve used a CGM, been lower than my blood test result. My predicted value has always been in the 5’s, and the blood test always comes back in the 6’s. No explanation. My red blood cells live a totally normal length of time, and I definitely do not have anemia.

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Did you mean 0.1% or a full percentage point?

My G6 sensors are usually within 10-15 mg/dL of my finger sticks… except…at high numbers (>200) or low numbers (<80).

I finger stick before every insulin dose, just like I did before CGMs. In fact, I finger stick way more than before the Dexcom. Before, I used the meter reading to dose, and then basically forgot about my BG level until the next insulin dose. Now, probably because I’m running lower than I ever was before, I’m checking to see how low I am. This is why I hate :rage: the misleading Dexcom commercials that claim, “No finger sticks, ever!”

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That’s what happens; calibrate from the app and it will adjust the figures in real time via the transmitter. I believe the transmitter back-calculates the old values and updates them. It does that when it detects the error itself but I haven’t proved it does that for calibrations too; it was difficult to establish that it was doing this for its own recalcs (but it was proved).

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I know about that, what i want is to be able to enter a reading when there is a data drop out or a false low. I get false lows sometimes when cycling. I do not want to do a calibration at that time, because often Dexcom will slowly get back in line with a finger stick.


With AndroidAPS the calibration (using BYODA) immediately appears as a “bolus check” entry; it seems to get entered into the algo (though I haven’t yet read the code so I can’t be sure). Manual bolus checks don’t, but it really is a choice of the implementors how to handle conflicting data. We have the choice of simply going open loop and doing our own corrections.

In fact even with the closed loop if I think I might have miscalced carbs I enter a late carb value (and “Cancel” the annoying AndroidAPS, “Do not eat when you have high Blood Glucose” directive). It doesn’t do an immediate bolus (because it has already done a correction) but it has the data.

That’s not going to work for me as I have an iPhone SE. I hope this phone lasts for a long time as all the phones available that will work with Dexcom and Tandem are huge, I don’t want to carry around a mini-tablet. My phone measures about 2.75’ x 5.75’ and I am happy with it.

My 2 concerns are:

  1. False highs and lows skew the proper delivery of basal with C-IQ.
  2. My endo checks Clarity which show lows and highs which don’t represent reality.

I am in day. 10 of a sensor. This morning I woke up with a nice steady data. Then a sudden plunge. I did a finger stick and callibrated. OK for 10 minutes then a spike above 150mg/dl. Did another stick/calibration and back normal. Since I did this screen shot BG is showing to have dropped from 103 to 89mg/dl.


@CarlosLuis what happens with insulin delivery in this situation? I don’t use a pump and it’s stuff like this that makes me nervous. I’m guessing that your false 150 is probably still within the control IQ range, but what if it was 180 or so?

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I agree. The trends are what I like looking at. A few months ago my endo said my CGM looked great! I wish I could remember the numbers, but when she told me what my HgbA1c was at 7.4, I was upset. How could one be good and the other bad. She told me that the HgbA1c was just a number. Being diabetic for 40 years, I know that my HgbA1c is the better number. It upset me so much!


Welcome, @selander41169! Nice first post! Feel free to introduce yourself in the introductions thread!