Dee what town are you in/near? Maybe I know somebody in a lab near you.
The only reason I know to have an INR over 3.5 is if you have had a clot while you were fully anticoagulated. By that I mean when you got to the hospital, you had an INR done and it was in the normal range. If you were taking warfarin but your INR was not done when you had the clot then it cannot be assumed that you were fully anticoagulated.
Do you have a clotting disorder ( Factor V deficiency, Protein C or S deficiency, lupus, antiphospholipid antibody syndrome etc)? These would probably caused you to have a clot at some time in the past.
When your INR gets above 5, you are at more risk for bleeding. I rarely change a warfarin dose for an INR below 5. I might hold one dose for an INR between 4 & 5 (it depends on the patient's history). I use the area between 3.5 and 5.0 as a safety net. The only bad thing about keeping your INR up to 4.0 is that you have less safety net and you are probably at higher risk for bleeding.
There are 2 schools of thought on warfarin management. They both come from the movie Predator. Jesse Ventura (Blaine) when is told that he is bleeding says, "I ain't got time to bleed". (Meaning - don't worry about bleeding 'cause it'll stop.)
On the opposite side is Arnold Schwarzenegger (Col. Dutch) who says, "If it bleeds ve can kill it." (Meaning - try not to cause bleeding - they might die)
Well, I'm in the Jesse Ventura camp. If you bleed you can put pressure on it, put ice on it, cauterize it, suture it, give vitamin K, give fresh frozen plasma, give clotting factors, even give more blood.
If you clot, you get a new valve or are paralyzed for the rest of your life.
I've seen an 80+ year old man with an estimated INR in the 80's who suffered no ill effects. I've seen 17 year old girls with stokes paralyzed on one side of the body.
That is why I do not worry about INRs under 5.0 and rarely hold doses when the iNR is in the 4 range.
