[anon125]

after using the freestyle neo of nearly a year, i see that the strips are expiring.
why do they expire?
so i bought new ones.
with seconds i had tested both the new and the old and got very different numbers.
is this normal?
do other brands do this?
old 5.7 and 5.6
new 6.8 and 6.8.
consistent anyway!
as a member of the 5% club this is a bit concerning.
freestyle support said go to your doctor, and readings are different each time
and other useless info in regards to my question.
Thanks all

 

[itissteve]

anon, strips perform a chemical reaction with blood. For many reasons (heat, ambient moisture levels, etc.) strips can deteriorate, so manufacturers put expiration dates on them.

Some folks think of that date as advisory and will use strips past their expiration date, especially if the results are not being used to treat critically high or low BG levels. Nothing I would advise personally, but some people do it.

Strips do have a range of values in which they can operate. Using a standardized test solution, my strips (Agamatrix) can display results within a range of 57 mg/dL and still be considered "good" (the range is printed on the vial).

Most strip manufacturers offer a "control solution" that you can use to test your strips and make sure they're within the range the manufacturer considers good. I use this solution each time I open a vial of strips.

I see Abbott sells a control solution for Freestyle meters. I'm not familiar with Freestyle meters or strips, but I would be inclined to get some control solution and make sure the new strips are giving you results you can depend on. Another option -- if you go through strips fast enough -- is to buy more strips and see what kind of results you get from those, though that road might still lead you to getting control solution.

 

[anon125]

thanks
the test solution numbers are very wide. really not much use

 

[VeeJay]

A couple years ago Bounty gave us the best explanation on how to use the test solution.

Regarding Meter/strip accuracy:

Most people rarely use the control solution to check their meters/strips. Here's the way I check and adjust my testing process:

The control solution is a constant. Meters and strips I've found will vary according to temperature; cold - higher readings - warm - lower readings.

On your test strip bottle there will be a control test range. On my current OneTouch bottle that number is 115-153mg/dL. That means that when you use the control solution in a test...anything between 115-153 is a viable number. Therein lies the ±15% of accuracy that the manufacture is given. In other words...you add 115 and 153 together, then divide it by 2 and you get 134. 134 minus 15% equals 114. 134 plus 15% equals 154.

So, this means that 134mg/dL is what that meter and test strip ideally should read if you use the test solution at the right ambient temperature.

Now, let's say I test a new bottle of test strips at the ideal temperature range. That range being the middle of the allowed temperature ranges for the meter and test strips. For my meter it's 43 to 111ºF...but my test strip bottle says 'Store test strips in vial only, below 86ºF'. Anyway...

Let's say I use the control solution to test a new bottle of test strips. The control solution test comes out 141mg/dL. Since the bottle reads 115 - 153 that means that the strips for that bottle read 7 points higher than what they should be...or, 5.5%.

From then on, when I test my whole blood, I figure that test is about 5.5% higher than it should be for that bottle.

As to temperature differences; In January I kept getting higher readings than usual. Couldn't figure out why. Using my usual method of Sherlock Holmes' deduction - "When you eliminate the impossible whatever remains, however improbable, must be the truth." I concluded it must be the temperature.

Upon rising in the morning, room temperature of 55ºF I took a FBG test. 132mg/dL. I waited an hour and took another test. 131mg/dL. The next day...did the same thing. FBG tests remained similar.

The next day I took a FBG test and it read 138mg/dL. I put the meter and the bottle of test strips in my pants pocket for an hour. My hour-later FBG test? 110mg/dL. Same thing the next day. I call that empirical evidence.

FWIW

 

[itissteve]

Gotta say, I have never done this. So long as the control solution ended up with a number in the middle-ish of the range on the vial, I called it good. Then again, I'm not sure I've ever had a vial of strips that seemed that far off center. Lucky, maybe. But I'll try it next time I open a vial.

 

[xring]

after using the freestyle neo of nearly a year, i see that the strips are expiring.
why do they expire?
so i bought new ones.
with seconds i had tested both the new and the old and got very different numbers.
is this normal?
do other brands do this?
old 5.7 and 5.6
new 6.8 and 6.8.
consistent anyway!
as a member of the 5% club this is a bit concerning.
freestyle support said go to your doctor, and readings are different each time
and other useless info in regards to my question.
Thanks all

At the doctor, my glucose was tested - 155.
When I got home a few minutes later, I tested with a test strip that expired FOUR YEARS AGO - 157. A second test with the same batch - 161. IMO, there is an expiration date on test strips for the same reason the instructions on shampoo says, "Lather, Rinse, Repeat." Or the instruction with out meters say, "Use a new lancet each time you test."

$$$

 

[anon125]

thanks all