So, in the above you state that Labs have made errors and you've experienced significant differences in results between the two meters. How do you conclude that the reading on the XS is correct and that the reading on the Coag-Sense is inaccurate? I'm curious because I rely upon the Coag-Sense. Thanks!
Years ago, I was convinced that the Coag-Sense was the most accurate. Its results seemed to be closer to the lab results than the CoaguChek XS. In many cases, I found the lab results to be close to an average of the results of the two meters.
I haven't done a lot of comparison testing in the last year or so, and the correlation with the labs was irregular - sometimes the Coag-Sense was closer, other times the CoaguChek XS was.
You asked how I determined which meter was correct - and I have to say that I don't know that either meter is 'correct.'
I'm leaning towards the XS for accuracy for a number of reasons:
Millions of people are using the XS (which in itself doesn't mean that it's necessarily right), but if there were significant errors near to 2.0, we would probably be seeing a number of strokes resulting from the meters overstating values. This hasn't occurred.
For self testing and at many (most?) INR clinics that use meters, the XS seems to be a standard (although I haven't done any extensive research to see if this is true). Again, complications that can be related to inaccurate results haven't been reported (or haven't been enough to get the attention of the FDA).
In my case, having an INR, as reported by my XSs (I have a few) is sometimes in the low 2s, there have been no bad events - although I still prefer to keep my INR in the 2.5-3.5 range.
I feel safe using the XS technology, a claim that I may have hesitated to make a few years ago.