# Re: [IP] Quick questions - need answer before Sat morning

```> So now I know my meter is 10 points higher
> than the lab's test.

Actually, you don't really know that your meter is always going to be ten
points off from the lab test.  Because accuracy is determined by
percentages, not actual numbers, it may be within the same percentage of
accuracy but a greater number of points apart in readings if your sugar were
high.

For instance, you said the lab was 77 and your meter read 87.  That puts it
at about 13% different from the lab.  Thirteen percent higher.

Supposing the lab showed your blood sugar to be, say, 230, your meter could
read 259 or 260 and still be 13% higher than the lab.

At the lower numbers, it was only ten digits off, but when your blood sugar
is higher, a larger gap in the numbers may still be the same percentage.  If
your original meter were 30 points off at a high reading, it may be
percentage wise no less accurate than your current meter.

What matters isn't so much the point value difference as it is the
percentage of difference.  The point value difference may change at various
levels.

Hope that helps put the numbers vs. the percentages into better perspective.

Kristen
dxd 1985, pumping since 1990
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