As many of you know, I've somehow wound up with a few meters - two or three (I think) XS and an XS Pro. When I compare the results, they are always within .1 of each other. Even a meter that my doctor said a patient left in the lab 'because it was too inaccurate' gave a good test result.
As far as labs being .4 below the meter - this is within the 20% acceptable result -- so, in effect, the results are equal. If your INR is high - probably 3.5 and above, your meter loses its accuracy - the results are slightly higher than they lab result - and the error increases the higher your INR is - it's a known issue. I suspect, though, that you keep your INR around 2.5, so a .4 difference with the lab shouldn't be seen as a major issue.]
As far as labs being .4 below the meter - this is within the 20% acceptable result -- so, in effect, the results are equal. If your INR is high - probably 3.5 and above, your meter loses its accuracy - the results are slightly higher than they lab result - and the error increases the higher your INR is - it's a known issue. I suspect, though, that you keep your INR around 2.5, so a .4 difference with the lab shouldn't be seen as a major issue.]
