Meter trouble
 

Found out my meter was inaccurate. It was giving me happy-making low readings - but they were a lie. Got my new meter today (free from Roche!) & compared the 2. Old meter - 122, new meter - 132. :tears:

Now I know why my a1C was higher than I thought it would be.

I thought I was doing so well & now I have to work even hard to get down to where I thought I was. Depressing. But I will survive! Tomorrow. Right now I wish I had some ice cream or something. Bad girl. :nono:

How do you know the first one is wron, rather than the second?

I checked it when I had my blood drawn at the lab. The lab fbg was 15 points more than my meter. The difference between the old & new meter is only 10 points, so the new one isn't perfectly accurate, but it's closer.

To know if your meter is off from the FBG from the lab test you would need to test at the exact same time, right before or after your lab draw. It could be different each day.

That's what I did. They drew my blood, I tested within a few minutes.

Well, that's a bummer then. I was hoping for a loophole for you.

The only loophole I ever seem to get is a noose. :(

Frustrating to be expecting a better result than you end up getting at the doctor's office. Espcially as you are diligently working the program, trying to make changes based on an inaccurate number.

The problem with all of the meters is they are only accurate within 10pts in either direction, so there will always be fluctuations. Heck you can even test 2 times in a row with the same meter using same finger, different drops of blood and get variation.

This article explains how they work and what affects a good reading or not:
Why glucose meters can't tell us our blood sugar level

The other factor too is that your A1c is a reflection of "continuous" BG, rather than your meter being a snapshot of the various times you test, so the meter is likely to not match exactly with your lab results. A1c is also affected by how fast your red blood cells turn over. I think it is that the faster the turnover, the less chance the cells become glycated, so you get a lower A1c.

I use the Ultra One Touch mini which was given to me at the doctor's office. It tracks maybe a bit lower than my lab tests, about 5pts maybe. But for me, I figure if I'm trending the right direction, then I'm ok. I'm not on insulin though, I can't remember if you are or not.

That's a good article on accuracy, or lack thereof. Don't think much has changed since 2012. Thanks Mycie, adding it to another thread.

Dr Bernstein has noted that the food we eat will produce glucose that easily can vary 30% of what we estimate. Speed of digestion, interaction with fat and protein, more or less carbs that we think etc

And if we inject insulin the rate at which it is absorbed into the blood stream will again vary by about 30%

So we already have two variables of 30%, and from what I understand from statistics this means that a meter varying only by 10% is accurate enough.

I keep a second meter, and should I get a reading that is unexpectedly high or low I test with the 2nd (different brand, different strips). I then go by the reading I think most likely.

I decided to raise my average BGs to 100 instead of 90. My retinopathy returned so I am back to a goal of 90 or a little below. Retinopathy is retreating, and when at 90 ophth. reports my eye shows signs of former retinopathy are actually healing. I am his only patient who reports this. He is a believer that diabetics should aim for truly normal BGs.

My point in all of this is that current meters are accurate enough to maintain very tight control. I don't react emotionally to any reading, just do the math in my head to estimate carbs or insulin needed to get back to goal.

That is great news!

Roche sent me a new meter - free. :)

Rob - I wish I could be less emotional about my readings. I tend to get happy when they are low, depressed or worried when they are high. I know better, too. Lately I've been taking a walk when they read high - it helps my mood a lot.

Replacement meter free...good!! :thup:

Should we replace meters periodically? Or should they perform the same for their lifetime?

I didn't get an answer to that question. But I would think that like all electronic things, they will go bad at odd times & should be replaced periodically. Or, like I did, take it with you when you get the "official" blood test & compare. My meter was maybe 5 years old. I'm a lousy record-keeper, so I'm not sure.