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Re: [IP] Accu-Chek Complete

On 14 Jun 98 at 21:57, Sam Skopp wrote:

> At 06/14/1998 - 08:47 PM Michael Maturen wrote:
> >Not to defend Accucheck, but the American Diabetes Association says that
> >a variation of +/- 20% is acceptable.
> 20% is quite a lot. I might react (no pun intended) quite differently with
> a reading of 80 than I would with one of 64.... or a reading that said 200
> vs 160. However, if I knew that my readings were always ~20% low, then I
> could easily compensate. The real danger is if it could randomly vary
> anywhere from 20% below to 20% above. Then IMHO the readings in this
> situation would be pretty much useless. As an example, if my actual BG was
> 100, the meter could give me any value between 80 and 120 and still be
> within ADA tolerances. If I were about to embark on some strenuous exercise
> I'd need to know which end of the spectrum it really was at, or risk going
> hypo. 

Lifescan has a couple of brochures available that explain this in 
detail.  Call their 800 number (800 227-8862) and ask for the 
brochure titled "Is my blood glucose meter accurate"  and the reprint 
titled "Sources of variation in blood glucose testing."  I think they 
may also be available on LifeScan's web page too.  

The key is to remember that you are measuring within broad ranges, 
and that you shouldn't have sharp boundaries for making changes.   
You need to be careful if you make a big change in insulin dosage 
based on a reading of 79 versus a reading of 81, because the meter 
just isn't that accurate.  Laboratory meters aren't that accurate 
either.  It's just like your car speedometer, which is likely to be 
+/- 10% - and maybe more due to tire wear, gear and cable wear and 
other odd factors.  If you weigh yourself every half hour over a 
twenty four hour period you may find your weight fluctuating as much 
as three to five pounds - so the question "how much do you weigh" 
gets fuzzy around the edges too.  

I guess the question really changes to whether we are measuring 
something that can be significantly counted (like bricks, books or 
coins) to measuring something that changes while the measurement is 
happening and is indirectly measured anyway (like blood glucose and 
most other chemical measurements.)  We are trained to think that a 
meter reading of 100 really means 100, when it can actually mean 
somewhere between 80 and 120.  The idea is to keep using the same 
instrument because the between instrument variation is at that level, 
but a single instrument tends to vary less...

Randall Winchester

* The views expressed here are mine and do not necessarily *
* reflect the official position of my employer.            *
* There's no guarantee on anything said here...
* If I say I understand something completely the only thing
* we can both be assured of is that I must have completely
* misunderstood something. 
Insulin-Pumpers website http://www.bizsystems.com/Diabetes/
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