July 26, 2012

Blood Glucose Meters versus Test Strips

Why is everyone blaming their blood glucose meters for being inaccurate? Even the Food and Drug Administration says the meters are not safe and accurate for the purpose many people are using them for. Read the FDA explanation here. If the FDA is this concerned, why have they not issued a warning or a recall? If meters are accurate or inaccurate, why do we need the test strips? Probably because most people think it is the meter doing all the testing, and they forget about the test strip that we insert into the slot in the meter for the meter to interpret the reading and convert it to a reading we can understand.

We need these insignificant little rascals because without them our meters would not be able to give us a reading of our blood glucose. Many doctors and endocrinologists hand the meters out for free as they have received them at no cost because the strip manufacturer knows that to use them, the test strips will be needed and in general, the tests strips are expensive.

Before you go ballistic on me, many of the manufacturers do have good assistance programs. You do have to apply for most of the assistance, but it is available to those in need. Do check with the manufacturer if you are in need of assistance and follow their directions.

I have written before about not wasting test strips. I have added additional information since then and I think it is time to cover this in more detail. First, make sure that you store and use your strips properly. The containers they come in are the proper containers to keep them in. Second, do not transfer the strips between containers as this can damage some of them.

If you are like me and have large fingers, the first few strips are often hard to remove from the container. The method I use is not approved, but it works for me. I keep a small plastic tweezers handy, that I have taken a short section of an appropriate width rubber band that I glued to the tweezer between the two sides (on each side) and one small piece on the outside (of one side) to gently pull the strip out far enough to get a grasp on it. I do this for getting out the first few. No, I did not say metal tweezers, as using them is a good way to damage the delicate strips. Check with your pharmacist for a plastic one, they are available, but may need to be ordered.

The original containers are made of special materials that help preserve the test strips and keep them dry. Keep the test strips in the original container and do not transfer them between containers. It is important to use the strip as soon as possible after removing it from the container. Close the container after removing the strip to use. Keep the container out of direct sunlight especially when taking strips out and do not expose the strip to direct sunlight.

Please do not put a few test strips in a baggie, in a purse, or wallet to carry them. The test strips are delicate and can be damaged beyond use. If you are out in nature, keep the test strips in the container, put the container in a small zip-lock bag, and then put this in a cooler or a Frio pack in the summer or an insulated bag during the winter. Keeping moisture away from the container of test strips is important.

Keep the container of test strips in a dry place. The bathroom or the kitchen is often the worse place to store your test strips. I will repeat what the directions are for my Accu-Chek Aviva test strips. I strongly urge you to read the instructions that come with your test strips.

Always store the test strips between 36° Fahrenheit and 90° F (2° Celsius to 32° C). Do not expose the test strips to heat, moisture, or humidity. Temperatures outside the required ranges, as well as moisture and humidity, can damage the test strips and lead to inaccurate results. Use the test strip removed from the container within three minutes or the results may be wrong, and you will need to repeat the test. You may use the test strip at temperature ranges between 43° F and 111° F (6° C and 44° C). You may also use the test strip between 10% to 90% relative humidity. Use the test strips only until the “Use by” date on the strip container. If the “Use by” date is missing or cannot be read, do not use the test strips. Do not reuse a test strip and properly discard a test strip once it has been used.

Always insert the test strip into the slot in the meter and make sure that the code number on the test strip container shows in the window. If the code does not show, remove the test strip and carefully reinsert to get the code. If it does not happen to show the code, discard the test strip and get a second test strip and repeat. Look at the meter to see if the drop of blood and the strip in the meter window is flashing. If it is, then use the lancet to prick your finger and carefully milk the finger to bring sufficient blood to the surface. Carefully insert the meter with the test strip area to wick up the blood into the drop of blood. Once the blood has wicked into the test strip, you may set the meter on a flat surface; wipe the excess blood off with a tissue or washable cloth. Then record the reading from the meter to a logbook and the time.

The above instructions have been summarized from the instruction sheet accompanying my test strips. There are other instructions that are spelled out on the instruction sheet and it is wise to know them if you are new to blood glucose testing. It also never hurts to review the instructions as they do change as technology is improved upon or like me I will be moving to a new updated test strip in the near future.

One instruction that has changed on my sheet, but I cannot say when it changed, is the instruction for preparing your hands or fingertips for testing. It used to instruct you to clean your hands with alcohol pads. Now the instructions state to first wash and dry your hands. I would correct this based on experience to, “Please wash your hands with warm water and soap, rinse carefully, and dry thoroughly before handling test strips. Never use wet or damp hands or fingers to handle the strip container or for removing a strip from the container. This should be the routine before using the lancet and wicking blood into the test strip.”

I have had two very good emails in response to my last blog informing me that when people are talking about meters, they are talking about both the test strip and meter in combination and that they function together as a unit. This is true, but I will point out that many people that are new to diabetes do not always make this connection and in fact two of the three emails I mentioned in my last blog were asking about why the test strips were not mentioned, and if it was the meters that were actually to blame. That was the purpose of this paragraph (the next paragraph down) in my last blog.

“As for meter accuracy distortion, this is understandable when they are jammed into bags, purses, pockets, and other places where they were not intended to be stored or carried. I have seen test strips wedged in the meter slots and jerked out. With this happening and no care of where the meter is stored, it is small wonder dirt, lint, and test strip particles could affect the accuracy of the blood glucose meter. This is delicate equipment and if you want accuracy within FDA guidelines, treat it accordingly. Some people even store meters and test strips in car glove boxes or on the dash in full sun and heat, so how can they expect accuracy?”

Proper storage of the meter is important for it to function correctly and properly read the test strips. To my readers, please know that there are many variables and that as things currently exist, we have reliable meters and some that are not so reliable. It is the test strips that determine meter accuracy and until our test strips can be calibrated to a more accurate degree of precision, we cannot expect our meters to be any more accurate. Please remember that when we talk about meters, most people refer only to the meter and in fact may mean the meter and test strip as a functioning unit.

Another reader brought up something I admit I had not considered. He stated, “I'm very aware of the problems involved in trying to set an accuracy specification. Very often a measurement device which actually has a tight performance spec when used properly in a stable-temperature environment ends up being given a very loose spec, because the maker is worried about what happens under less favorable conditions.”

I would like to express my thanks to those that sent emails, even some of the unpleasant ones. I was very appreciative of the emails packed with information, some of which I used above, as they added to the information. I am still sorting through the information and may add some to another blog.

For a very incomplete listing and information about blood glucose meters as a meter and test strip unit, some of you may be interested is this PDF file from Diabetes Health web site. Also read this by David Mendosa published on July16, 2012 and follow the link provided for a different perspective on selecting blood glucose meters.

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