Glucometrs and Lab-Roughly How Reliable?

[wa5ekh]

I have been in professional labs my entire life. When we measure voltage, temperature, meters, inches, pounds, time .....anything! and we want to know how accurate, or inaccurate, we are ...we must have some sort of a standard to compare to all previous measurements.
One day I was diagnose with type 2. Suddenly I was using a glucometer without a standard. My doctor sends blood to a lab and I don't know what standards they are using(and I get cutoff when I inquire at any level!!). The glucometers seem to "say" they are accurate +_20%(80-120 mg/dl are the same, and 100-140mg is 120+_20%approx.). The only standards I can find are not near enough the 100 mg/dl targets to be of any real use (50, 160, 200, 240-350).

No personal standards are "easily or usually" available. In the literature I read temperature, technique, strip variations, metering variations, certain drugs(probably with certain individuals), illness, ....and several other things can lead up to 50% error (the highest I have read or experienced...without standards).

I have been diagnosed type 2 for 4 years now , gone to hundreds of support groups meetings,…seen various doctors, ADA, Joslin, attempted to engage numerous academics and ...including this list and others ....and have never been able to resolve this.

I have taken several 1-3 month breaks(this was the latest) over the last 4 years for this "quest", tried to calm down out of complete frustration, and each time returned more determined that I will not accept this important, if not life threatening gap " in this medical technology continue to exist, if at all possible.

I realize very few understand this simple concept of using a “standard solution” routinely, but it really isn’t complicated, and can be quite simple. Most people react negatively because their Doctors or their Diabetic training has not mentioned this in their training. It appears to be “new”. As a Diabetic I contend it should not have been overlooked. This could (and in my opinion probably does) have the effect of giving you better control and “understanding” of exactly what effects your BG levels.

If we don't eliminate the confusion, then we must live daily with this confusion. I see this in every diabetic I know.

Has anyone else noticed this? Any suggestions, similar experiences ? I don’t think we can ignore or suppress this issue any longer. We need solutions. I have never trusted glucometry to less than 50% accuracy. Professional labs seem to be immune from any real accountability to the patient. This is just unacceptable.

[Coravh]

I can't give you the technical details, but I know that here in Canada, the lab techniques are fairly stringent. Of course they will not (absolutely will not) give you what the standard error is, but that's life.

The bottom line is that if you want to check the accuracy of your meter, you will have to test when you have your labs drawn. There will be some difference because the lab uses whole blood, but it will give you an idea of what your individual meter is like. I have a freestyle mini and it has never been out by more than 6%, so I'm very happy with that. You need to find out how accurate your meter is. I don't find the 20% standard to really mean anything. Meters vary individually quite a bit. Check it periodically when you have blood drawn.

Cora

[nowhere-child]

Couple things come to mind...the first being that I see your frustration (having been married to not one, but TWO engineers in my life! My first husband was known to perform temperature accuracy tests on my oven each week)

If you have a grave concern over the general accuracy of your glucometer, ask your doctor to let you have a lab glucose drawn. Take your glucometer to the lab with you. Check a fingerstick glucose at the same time as your blood is drawn. That will give you a rough accuracy comparison. As long as the numbers you get (and it will take a day or 2 to get the lab figure back) are within about + or - 10 points, your glucometer is accurate. STOP NITPICKING. I've never heard of a 50% error rate. If home glucometers were that inaccurate, they would be ABSOLUTELY WORTHLESS. Now, there may be times if your storage conditions or technique was awful that there could be errors that high, but that would not be something that would happen often, if at all.

Store your strips and glucometer as instructed, wash and dry your hands well prior to testing, follow testing instructions...and you should get an answer that is very accurate. Your blood sugar can change from minute to minute, so you will never, ever get "THE" answer you are looking for. In the hospital, we run controls on our glucometers each day, but are only looking for a "pass or fail" on high and low controls. We do NOT get into the minutia you are talking about. For all practical purposes, if you buy a well known brand name glucometer, it should be accurate. If you are overly concerned, you can double check it as I described by comparing a lab draw to your own glucometer, but be aware that a fingerstick result CAN BE A BIT HIGHER OR LOWER than a serum draw. How much higher or lower is not known, but in general the result should be in the same ballpark. When I would be concerned is if say, your glucometer said you were one number, and the serum draw said something outrageously different. IN GENERAL, the numbers should be close. And close is a good as you are going to get. If you get a difference that you are concerned about, call your doctor and ask if it is something to be worried about.

The reason no one can tell you exactly to the decimal point the differences, is that in medicine, results can vary. Look for the same ballpark figures. That's the best you will EVER GET, so I suggest you try to accept it. I do not believe the 50% error rate you quote, and if you found it somewhere, it was a CYA statement to cover someone who perhaps stores their equipment somewhere ridiculous or who performs the test completely in the wrong manner.

Again, if your storage is correct, if your technique is correct, and your glucometer is not some el cheapo brand from some wierd place, you should be able to trust your numbers. If you can't get over this, you will simply be frustrated forever.

(Are you SURE you aren't my ex-husband? He was convinced my oven was terribly inaccurate as I described before, and conducted elaborate, ridiculous experiments all the freaking time. Drove me crazy!) I got rid of him.

[wa5ekh]

I have done the literature searches back 30 years to present. I know the techniques. These "gestimates" of conservative error are just hopeful self-deception. Without a referencable standard solution your glucometer could be only in the "Ball Park" (NO specific reading). This is just flagrant dismissal of the basics of good measurement. Your GUESSING. I suppose you don't want to deal with the reality. I have seen this every day since I was diagnosed 4 years ago and still seems inconcievable that so many professional health workers do not get it or blow it off. i'm sorry, but this has been ignored too long!

[Mommyof4]

Sorry, but taking a meter with you to the lab won't do you much good. Labs use blood plasma when testing blood sugars while glucometers use whole blood. The difference in what part of the blood in being tested will give you a different number.

As for the "Industry Standard"..... Every diabetic out there would like one. I would love to take blood sugars within minutes of each other and get the same number. I would love to put my Accucheck and my Lifetouch side by side and see the same number. Sadly, all of these meters are being manufactured by commercial companies who happen to sell medical equipment. They do their research on trying to build a better meter which usually boils down to a new button or a new connection to your computer. Little is done for accuracy.

Most research done today is for a cure. Scientists look for better ways to control this condition while looking for a way to eradicate it completly. Our job as the patient is to do our best to control it by diet and excercise. Very few days have I done my best.

I also don't think that diabetics out there are simply settling for mediocrity. I am a wife, and mother, a diabetic, and so on and so forth. I choose not to live every minute of the day thinking about how tight things should be controlled or how I am not getting all of the answers to all of my questions. I sit back and think about how 50 years ago I would have been told that I couldn't have any children while today I have 4. I thank God for how far diabetes research and care have come in less than a century.

I count on my glucometer because it is more accurate than a feeling. It is more reliable than my guesswork. Do I wish they could offer something better? Yes. Am I willing to become consumed by it? No. I have much more to live for and think about.

Sorry to say but it sounds to me that you might be too close to the situation. It might be the equivalent of a Dr getting sick. It's hard to have your own knowledge yet put your care in someone else's hands. If the anxiety becomes too great, you might want to find someone to talk to. Good luck