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Test strip anomalies

Ricky

Ricky

Well-Known Member
Messages
297
Location
Merseyside
Type of diabetes
Prediabetes
Treatment type
Diet only
Does anyone else find that from batch to batch the test strips vary a lot. My current batch from Freestyle lite are reading <4.5 , my last batch was <6 yet both batches passed the control solution tests. I find it very frustrating!!
 
david.bligh said:
How do you know it's your test strips? Could this not just be your blood?
Click to expand...

Because I always now test one of the old and one of the new batch in the same drop of blood. I really don't think my blood sugar can be so consistently low (<4.7) with what I am eating :) I will be getting a new batch of strips next week again. If it were that low I could be eating more carbs!!!! (Thinks cakes and biscuits :D )
 
If you think there's an issue with your strips, ring abbott Diabetes Care. they are always willing to try to sort out a problem and will certainly replace the strips.
Hana
 
hanadr said:
If you think there's an issue with your strips, ring abbott Diabetes Care. they are always willing to try to sort out a problem and will certainly replace the strips.
Hana
Click to expand...
When I phoned Abbott - they yet again sent me a pack of control liquids and the test strips are always within the boundaries , but the boundaries are very large!!!
 
Agree with Ricky. Had a big diff from the same blood spot taken within seconds on two strip batches. Got told "blood chemicals could have changed in that time" nonsense.
 
Ricky said:
<snip>
When I phoned Abbott - they yet again sent me a pack of control liquids and the test strips are always within the boundaries , but the boundaries are very large!!!
Click to expand...

The acceptable range for the control solutions gives you a feeling for the expected accuracy of the strips.
I think the message is that the test strips give you guidance to which range you are in, but they are not incredibly accurate.

I have found that batches seem to be consistent but there can be differences between batches.

So don't get hung up on 0.1 difference in a reading - look more to the trends and the whole numbers.

Cheers

LGC
 
Personally I think the batch I have now are a whole 1.0 out!!! We'll see when I get the next batch!! Abbott tell me that a 10% or was it 20% (can't remember) variance is acceptable.
 
I have noticed this seems to happen with my Freestyle Lite strips too.

Have you received the letter from Abbott too about the new ranges for the testing solution? If they are under a certain Batch number the high range is one range and if the batch number is higher than a certain figure then the high range is different.... :crazy: How does that work then? Surely a test is a test and should record the same figure with that solution!!

Regards
Angie
 
Yes I was told over the phone and also sent a letter explaining it with the control solutions. All sounds strange to me as well- like a cop out!!
 
How interesting! Thanks for that link. I was also correct with the 20% accuracy. Well I suppose they are not a complete waste of time but it does explain why some people can't manage their insulin if they are relying on the accuracy of these test strips. I wonder if some brands are better than others? For the price they are I am so surprised at the inaccuracies that are allowed.
 
If you look at these inexpensive meters compared to the lab equipment then you can see why the meters wouldn't be so accurate. Mind you, they're a lot more accurate than the BM sticks we had before, where you had to match the stick result to a colour chart printed on the container. But even they were far superior to the urine tests we had before the BM sticks ;)
 
urine sticks ?!?! Luxury ;)

I was given a set of test tubes, a pipette and a bottle of reagent tablets. It was 5 drops of pee + 10 drops of water... add a tablet and wait for the violent fizzing to stop, wait a further 10 seconds, shake gently and match the muddy mixture against a colour chart.

OK, this is getting too much like a Monty Python sketch ;)
 
robert72 said:
urine sticks ?!?! Luxury ;)

I was given a set of test tubes, a pipette and a bottle of reagent tablets. It was 5 drops of pee + 10 drops of water... add a tablet and wait for the violent fizzing to stop, wait a further 10 seconds, shake gently and match the muddy mixture against a colour chart.

OK, this is getting too much like a Monty Python sketch ;)
Click to expand...

Sounds a bit like how I check my fish tank water for nitrates! :lol:
 
Grazer said:
robert72 said:
urine sticks ?!?! Luxury ;)

I was given a set of test tubes, a pipette and a bottle of reagent tablets. It was 5 drops of pee + 10 drops of water... add a tablet and wait for the violent fizzing to stop, wait a further 10 seconds, shake gently and match the muddy mixture against a colour chart.

OK, this is getting too much like a Monty Python sketch ;)
Click to expand...

Sounds a bit like how I check my fish tank water for nitrates! :lol:
Click to expand...

You should get some fish sticks. Oh, wait... ;)
 
angieG said:
I have noticed this seems to happen with my Freestyle Lite strips too.

Have you received the letter from Abbott too about the new ranges for the testing solution? If they are under a certain Batch number the high range is one range and if the batch number is higher than a certain figure then the high range is different.... :crazy: How does that work then? Surely a test is a test and should record the same figure with that solution!!

Regards
Angie
Click to expand...

Looks to me as though the test strips were reading low for the higher ranges so they've reformulated the test strips to read higher (hopefully more accurately).
So you expect different results from before and after the change.
There have been reports of Abbott Freestyle Lite meters reading lower than others.
 
robert72 said:
I was reading this article a few days ago which sheds a bit of light on the accuracy of blood glucose meters in comparison to lab test equipment:

http://www.aacc.org/publications/cln/2010/may/Pages/CoverStory1May2010.aspx
Click to expand...

Good reference :-)

For real numbers, this suggests that if you have a BG of say 10 mmol/l the meter is within spec if it reads between 8.0 and 12.0. I assume you use the test solution to calibrate your test strips so that hopefully if a random sample (say 2 or 3 out of 50) are consistent then you know if the current batch is reading high, low, or on the money.
This does suggest you might have to sacrifice up to 10% of a 50 pack to calibrate the batch against high and low solutions.

Interesting bit is that for high values they quote a percentage +/- but for low values they quote an amount (which a quick calculator bash suggests is 16%).

More worrying is that the acceptable error on lab equipment is between +/-4% and +/-10%.
O.K. this is for BG monitoring but what if it is similar for HbA1c testing?
This would suggest that for an HbA1c reading of a true 8.0 you could get a lab reading of between 7.7 and 8.3 (4%).
If I had a reading of 8.3 and it went down to 7.7 on the next test I would think I was doing really well on my chosen regime. :shock:

So - again I say decimal points on the values seem meaningless and shouldn't be given undue weight.

Perhaps this should be emphasised more to those beginning or continuing testing.

This could also partially explain why the HCPs aren't strongly behind home testing (assuming that they are aware of the accuracy issues).

Cheers

LGC
 
I think these meters are for less accurate than we sometimes give them credit for. Bayer swear that the meters I have are tested to be +/- 4% at mid ranges. I phoned them with a series of results taken across 2 different bayer meters on different strips, taken simultaneously from the same finger, and got readings 20% different. So even if one meter was error +ve and the other -ve, they would have to be 10% each. I got all sorts of nomnsense answers, from their "specialist", about "even in a few seconds things can change; if the blood is exposed to air for more than a few seconds it can change" etc.
Independent tests done in a lab showed AVERAGE errors of 15% across a range of meters.
I wonder of they're like speedos in a car. Car speedos are ALWAYS high, never low, so a person can't claim their speedo was wrong when caught speeding. Rules state a speedo can be up to, I think, 10% high but 0% low. So to be safe, they're always set high.
I wonder if our meters are the same, but always set a bit low for safety so hypos are not missed by people thinking they are higher than they are. Just a thought. I'm certain my meter always reads a bit low - like at least 10% (bayer contour)
 
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