We do have Canadians here, and I thought we had at least one who home-tests.
This weekend, I drove to a cat show in San Antonio -- about 5 hours from my home. A friend who lives about 45 miles west of me rode down & back with me. Noreene is a RN, works in surgery at a hospital in her town.
I told her about vr.com and the myths of dealing with warfarin. Told her that warfarin dosage is dictated more by activity level, general health, illnesses and Rxes we take, not so much as by what we eat (as per Al Lodwick). Told her about how some doctors scare the dickens out of patients new to warfarin by saying you have to limit this, this, this, etc.
I told her that when I eat broccoli as a veggie, it's about 1/2 of a frozen package of spears. And I don't eat a salad the same day.
She agreed on all I said.
I noticed that when I changed to a very low-fat lifestyle in June 2004, my INR shot up. When I boosted my exercise level, my INR went down.
Like others have pointed out, we are more cautious about situations where we might have a head injury. But non-warfarin users need to be just as cautious too!