It’s been over 40 years since we put a person on the moon.  We have nano technology that is way beyond me.  I can fit about 5,000 songs on my iPod nano which is almost paper thin.  Apple has a laptop that fits into an envelope.   There are cars that can run without gas.  We have amazing insights on DNA sequencing, chromosome mapping, etc.  I can talk and see someone thousands of miles away through my computer without costing me a dime (Skype).  The list goes on and on.

And yet…….

I still have to freakin’ code my meter every time I get a new bottle of test strips where the code is different than the one I’m using.  WHY?  Seriously?  I find it very hard to believe that this annoyance can’t be overcome very easily.  I also wonder if the code really matters.  For example, does putting in the wrong code and testing give a different result than the correct code?  This calls for a little experiment.

My Experiment

Below you will find the results of 10 consecutive blood glucose tests.  The first 5 were done using the correct test strip to meter code.  The second 5 tests were done where the code was not correct between the meter and test strips.  The results are interesting.

What immediately stands out is the variance between the average correct and average wrong test, which is 63 mg/dl.  That really blows my mind.  In essence, you could expect a 63 mg/dl swing down when the code is incorrect.  The second thing that jumps out is test 5 where the number went from being around 145 to 207.  A 61 mg/dl swing between two tests for no apparent reason is cause for concern.  Keep in mind the 5 tests were done within minutes of each other if not 30 seconds or so apart.  The results and variance is pretty scary because I would certainly treat a 207 differently than a 146.  I use the OneTouch UltraLink meter with LifeScan One Touch test strips.  I’m not trying to be critical of LifeScan or Medtronic; I’m simply trying to understand the accuracy and coding need.

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What They Said

This was the first time I actually read the little folder paper in the test strip box.  LifeScan has a caution in the writing that says:

“Matching the code on the meter and the code on the test strip vial is essential to obtain accurate results.  Each time you test, check to make sure the code numbers match.”   …”a clinical test was done and showed that the variability from test strip to test strip in blood tests was 3.2% or less.” [LifeScan]

Here is a quote from a study done that warns about miscoding meters:

“In this study, for certain miscoded meters, the probability of insulin error of plus or minus 2 units of insulin was 50% as compared to 8% for correctly, manually coded meters.  The probability of insulin dose error of plus or minus 3 units of insulin was 23% for the miscoded meters but only 0.5% for the manually correctly coded meters.”

Summary

My test using a very small sample size yielded a 6% variance mainly due to the test #5 that threw off the average.  Besides #5, the results were very close when the code matched from the meter to vial.   On average, there was a 63 mg/dl variance between when the meter was coded correctly and when it was not.  Make sure you code your meter correctly when changing test strip vials.  Seriously, this could mean a severe life-threatening episode by simply having the wrong code entered into the meter.  Although I still don’t understand WHY I still need to code (after 10 years), I do understand the importance of accuracy and will take extra care to ensure correct coding.  Coding may seem like an annoyance, but it could also cause a high/low just for the code being wrong.  We have enough to deal with as insulin dependent diabetics – can’t we get rid of the code?

Question

Does anyone know really why we still need to code meters?  They say it’s to match the vial of strips to the meter for accuracy, but WHY?  I know there are some meters on the market that are codeless.  Are they less accurate?  I doubt it.