It is no surprise to me to read this story.
For many years until I retired a year and half ago, I was convinced there was a significant problem in accuracy through my own observation. I convinced all my patients not to go for it. Unfortunately many practitioners do this test in their own offices to make a few easy dollors.
Most practitioners are not fully conscious of the inaccuracy of finger prick accu check for blood sugar, either,
which is not as consequential as the measurement of INR.