Expiry date on test strips

[LittleGreyCat]

I have been diagnosed as T2 now for just over 2 years now.
Soon after I was first diagnosed I was given a meter by the DN, and then had a top up prescription for test strips and lancets.

The new lancets put me right off testing as they were a heavier weight than the ones which came with the meter (yeah, idle wimp, I know) but I am now reviewing my diet and general lifestyle as my HbA1c is sliding just a little.

The main driver is a loss of sex drive.
I thought (hoped?) it was low testosterone levels but I've had a blood test and my levels are fine.
Shame, in a way. A tab of gel is a straightforward quick fix.
The next suspect is diabetes itself so (once I've got my statin problems sorted out) I may start on Metformin or similar.
So I am revisiting my BG levels and testing again.

Now I have loads of lancets and have decided to not be such a wimp, especially as the thinner lancet now won't get blood out of me. This is possibly because my hands have toughened up with manual work including laying concrete blocks.

So to cut to the chase; I can now get blood out (ouch) and test, but my test strips go out of date in about a month.

Is this date like the 'best before' on food, where you expect it to last a bit longer?

Obviously the test strips will not work on Monday then stop completely on Tuesday because the date has passed.
Presumably the date is when it is estimated that the degree of error in testing cannot be guaranteed to be below acceptable levels.

So how long after the expiry date is it reasonable to use the strips?
I am using them quite quickly at the moment but intend to ease back on the testing once I have a baseline then ramp up again when (if) I go on the drugs.

Cheers

LGC

 

[catherinecherub]

Hi LGC,
I would phone the manufacturers and see what they say.

Catherine.

 

[MaryChristine]

You could perhaps ask the meter manufacturer for some (free) control solutions, usually used to check the accuracy of the meter. But if your strips give you the correct results for the control solutions and you have no reason to suspect there is anything wrong with the meter, it is likely the strips are ok.

You could double-check by testing the meter with control solutions on a couple of in-date strips, which you will probably have to acquire soon anyway.

Hope this helps.

Best wishes
MaryChristine

 

[badmedisin]

I've had to do that when it all went wrong on the prescription front (always order extra in time for Xmas...).
Just change the date in your meter and test the strips with control solution. If you phone the manufacturer of the meter or strips they will usually just send you some without charging. Same for batteries, which is nice. Obviously it'd be worth getting hold of some new strips asap if you can.

 

[LittleGreyCat]

<snip>
Just change the date in your meter and test the strips with control solution.
<snip>

Interesting.
Are you suggesting that the test strips have an in-built date and will be rejected by the meter if they are out of date?
I don't really want to tinker with the date and time because they are used by the diagnostic software which comes with the meter.

As suggested I will get some control solution just to check the strips.

Cheers

LGC

 

[sugarless sue]

Blood glucose monitors measure the amount of sugar in a sample of blood using a complex chemical process. Within the test strip the blood is mixed with glucose oxidase, which reacts with the glucose in the blood sample to create gluconic acid. Another chemical within the test strip, called ferricyanide, then reacts with the gluconic acid to create ferrocyanide. The electrode within the test strip then runs a current through the blood sample and the ferrocyanide influences this current in such a way that the concentration of blood glucose within the sample can be accurately measured within a fair margin of error.

Source E How.

The reason there is a use by date is because of the degradation of the chemicals in the strips. The same principle as use by dates on medication because chemicals degrade and therefore, in test strips, would show incorrect results.

Therefore changing the date in your meter would make no difference.

 

[jocat44]

On the meters I have got you are unable to use test strips beyond the use by date because all the meters have an inbuilt date and time. It wouldn't be advisable to alter the date and continue using them becasuse of degradation of the chemicals which make a strip work and give a reading. Lancets on the other hand can be used easily after use by date.
Jo

 

[Synonym]

Lancets on the other hand can be used easily after use by date.
Jo

One wonders why there should be an expiry date on lancets anyway - any ideas :?:

There may well not be any valid reason and it may be put there for the same reason that there is a use by date on a writing pad which we bought recently! :roll: :lol:

 

[MaryChristine]

Re expiry date on lancets - possibly to do with sterility. The manufacturer will not be able to guarantee that the lancets remain sterile and safe to use for ever but they can guarantee them for a limited period if they have tested samples and generated data to show that sterility is maintained for at least a specified length of time after manufacture. They can then set an expiry date within that time limit.

The lancets may well be perfectly safe to use well after the expiry date but the manufacturer would be unlikely to accept responsibility for any infection that occurred.

No idea about the writing paper though.

MaryChristine

 

[pleonism]

Hey LittleGreyCat,

I do a lot of studies and due to that I also have alot of extra test strips. I don't know anything about the chemicals degrading but I standardly use expired test strips. I do use a control liquid but I also test it by using a test strip that is not expired at the same time and from the same sample as the expired one. In the U.S. our meters have been set to show a error code for expired test strips but I take the battery out and reset the day to before the expiration date. I have used old test strips on a new meter and an old meter with the same sample and been off by a minimal amount. I have also tested with the same sample with two different meters with a similar out come.

so I guess what I am saying, and I am not an expert of any sort, is that check with a control and/or newer strips every couple of weeks to month to be sure and you should be ok.

I would also like to say that I have not sampled from my finger in over 3 years. you should be able to test from your forearm, assuming your meters in the UK are the same as U.S. meters. No finger= no pain to almost no pain......


Good luck,

pleo

 

[cugila]

Hey LittleGreyCat,
I would also like to say that I have not sampled from my finger in over 3 years. you should be able to test from your forearm, assuming your meters in the UK are the same as U.S. meters. No finger= no pain to almost no pain......

pleo

Any member considering using AST (alternative site testing) should discuss with their GP or HCP as recommended in the instructions for every meter and it's use. Only then should this be used if advised. There is a time delay depending on which area is used, other than the fingers.

cugila
Forum Monitor

 

[LittleGreyCat]

Noted that if a meter can detect an out of date test strip then each individual test strip must contain an internal coding of the expiry date.

Logically the meter must know the current date and time and be able to compare that to the encoded date and time in the strip.

Does anyone know if this is true for all strips and all meters?

I suppose I could check by rolling the date forward on my meter then inserting a strip.

 

[Anonymous]

Blood glucose monitors measure the amount of sugar in a sample of blood using a complex chemical process. Within the test strip the blood is mixed with glucose oxidase, which reacts with the glucose in the blood sample to create gluconic acid. Another chemical within the test strip, called ferricyanide, then reacts with the gluconic acid to create ferrocyanide. The electrode within the test strip then runs a current through the blood sample and the ferrocyanide influences this current in such a way that the concentration of blood glucose within the sample can be accurately measured within a fair margin of error.

Source E How.

The reason there is a use by date is because of the degradation of the chemicals in the strips. The same principle as use by dates on medication because chemicals degrade and therefore, in test strips, would show incorrect results.

Therefore changing the date in your meter would make no difference.

I would have thought that Sue's post quite clearly explained why you shouldn't use expired test strips. Do you also take out of date medications then or eat expired foods ? !!
The reason they have expiry dates is because of the degradation of the chemicals in the strips. They will no longer give accurate readings after the expiry date just as medications may not be as effective after their expiry date.
Your health,your choice.

 

[LittleGreyCat]

I would have thought that Sue's post quite clearly explained why you shouldn't use expired test strips. Do you also take out of date medications then or eat expired foods ? !!
The reason they have expiry dates is because of the degradation of the chemicals in the strips. They will no longer give accurate readings after the expiry date just as medications may not be as effective after their expiry date.
Your health,your choice.

Have you read all the discussion?
I think we are all aware of why test strips get less accurate with time.
I also attended a very instuctive talk recently by someone who managed new drugs through their life cycle and I am also aware of the way the expiry date on drugs is set.

You say "They will no longer give accurate readings after the expiry date".
This is misleading. It will be true eventually but not necessarily immediately.
They MAY not give an accurate reading - but not all strips magically become inaccurate on the same day.
Apart from anything else it would be a miracle if they could then be guaranteed accurate to the day before!

The good advice given aready is 'test a strip with the control solution'.
This will show you if the strips are still accurate.
The interesting issue raised is that some test strips have an encoded date so the meter may refuse to use them after this date.

And yes, I do eat food after the 'best before' date when I consider it to be safe.
I would also take expired medication of I considered it to be safe.

Try and think about this logically.

If something has a very short shelf life (food, medication, whatever) then the risks of using it shortly after the expiry date can be quite high because it obviously degrades quickly.

If you have something with a five year shelf life then using it a week after the expiry date is unlikely to be dangerous because of the slow rate of decay and the built in safety factor applied by the supplier to ensure that virtually all the goods last up to the expiry date.

These dates are not some form of arcane magic - they are an assesment by the supplier of the probability of the product being no longer fit for purpose at a given date.

With an understanding of how these dates are generated you can then decide on an individual basis if you feel safe in using the product after the expiry date.

If you are not comfortable making that decision then follow the dates.

Are you aware of a website who say "We are the UK's BIGGEST online sellers of clearance, short-dated and out-of-date approved food and drink."?

For many years the needy have been fed by charities who collect foods which are past their use by/sell by date (but which are still perfectly edible) from major supermarkets.
There are now some major businesses such as the one above trading in these items.

Also interesting reading is http://www.health.harvard.edu/fhg/updates/update1103a.shtml.

"Most of what is known about drug expiration dates comes from a study conducted by the Food and Drug Administration at the request of the military. With a large and expensive stockpile of drugs, the military faced tossing out and replacing its drugs every few years. What they found from the study is 90% of more than 100 drugs, both prescription and over-the-counter, were perfectly good to use even 15 years after the expiration date. "

Plenty of other interesting information available by Google or your search engine of choice.

Test strips are obviously not like aspirin, where 90% effectiveness is still pretty good, but if there is a two year period when they are 'in date' then using them for two weeks after the expiry date does not seem that risky.
Please also note that if you are worried about the accuracy then you should regularly check your test strips with the control solution and this is likely to become more important the closer they get to the expiry date.

HTH

LGC

 

[cugila]

I think the point here is why should anybody want to use expired test strips ? Is it solely due to costs ?

You are correct in that they don't immediately become inaccurate the day after the expiry date. I don't think that was meant in any of the previous posts. Pehaps the wording was not perfectly correct, but the sentiment is the same. They have expired, throw them out. If you wish to use them you just need to be aware that your readings may not be accurate. Believe that or not.

However, almost, or nearly might be fine for some. Many of us here want to be as accurate as possible, (that's another topic ) That's why I personally would never use expired products, even if it did save me money......my choice. What others do is entirely up to them.

The manufacturers clearly state that they will no longer guarantee the accuracy of any readings if an out of date test strip is used. This as stated before is due to the degradation of the chemicals in the strips......I think everybody now accepts that. Changing the date in a meter doesn't magically stop any degradation that may or has, taken place.

You mentioned the control solution......that only tells you that the meter and test strips are working correctly within the parameters specified. It does not tell you that your blood reading taken using one of the expired test strips is accurate a week or month down the line. It may be, then again, because of the aforementioned degradation of the strips it may be out, sometimes even significantly.

The control solution does not tell you that a strip is going to give you an accurate reading once it has started to degrade, just that it is within the tolerances. Which begs the question, is the control solution viable, within date. Usually these have to be used within 3 months of opening too.

The manufacturers are very clear. Do not use test strips etc after the expiry date. If you choose to ignore that advice, that is entirely up to you. However, we prefer that newly diagnosed get the best possible advice in all circumstances and that is what we advocate here. Everybody has a choice in what they do. Right or wrong.

cugila
Forum Monitor

 

[vicsetter]

A bit puzzled by this one,
a) all my test strips have at least a year before expiry
b) apart from the softclix carrousel lancets, all my lancets are the same size and I've never noticed an expiry on them. There is also no expiry on Novofine needles.

 

[tmylward]

Sometimes I can't believe that my blood sugar level is what the meter says. :shock: .

I wash my hands again, and redo. Hey presto it's a whole point down.

Then once more just to prove it and it's back where it was. :roll:

What more can one assume other than these machines are not as accurate as we would like to think...

 

[vicsetter]

Had a similar thread on another forum. I use 2 meters the USB Contour and the MyLife Pura. The Pura fairly consistently reads lower by as much as 25%. Sometimes they are fairly close. Meters aren't supposed to be all that accurate (like +/-15%). Obviously as your reading gets lower it will seem more accurate. Can't explain your 3 reading scenario, I have found consecutive readings with the same meter to be within a 0.2 of each other.
Silly question: have you run a test solution on your meter/test strip batch recently? You could have a fault.