G
Guest
We have been putting data from my clinic on an Excel Spreadsheet for over four years. I have some pharmacy students who are doing chart reviews and we have enough data that I wanted to let you know what we have found.
We have had over 11,000 patient visits. There were just under 900 people involved. We had just about every reason that you could think of for taking warfarin. The ages ranged from 5 months to 107 years. So far we have reviewed about half os the charts and this is what we found.
At about 60% of the visits, the INR was in the desired range give or take 0.2 INR units.
There were about 460 patient years covered.
There was 1 episode of minor bleeding per patient year. In most studies, major bleeding is defined as life-threatening or requiring 2 units of blood to be transfused. We used this definition. Anything that required the person to stop what they were doing to attend to the bleeding up to a bleed that required 2 units of blood was defined as minor bleeding. For example, if someone blew their nose and there was a spot of blood on the handkerchief but no action was required, this did not constitute minor bleeding. But if someone woke up to find a spot of blood on the pillow case and they had to wash it, this was minor bleeding. Almost all minor bleeding was from the nose.
Clotting events occurred at the rate of 2 per 100 patient years. Most were minor clots in the legs. Most occurred when the INR was low when the person stopped warfarin. Most required no other treatment than re-starting warfarin.
There were 25 major events. These included strokes - both clotting and bleeding, one heart attack, gastrointestinal bleeds, bloody noses, etc. This is a rate of a little over 5 per 100 patient years. All but 4 of these events occurred in people who had serious conditions besides the one that caused them to be on warfarin. These conditions included being very frail, alcoholism, having heart failure caused by being hit by lightning, lupus, extreme anorexia causing the INR to be elevated at many visits etc. So when you look at people who had only one major condition, (heart valve, atrial fibrillation, uncomplicated blood clot in the leg etc) then major events - clotting or bleeding occurred less than once per 100 patient years.
There were three deaths - one was a suicide. That person had previously had a bleed into the knee joint and he felt it coming on again. He called a relative and said that he could not go through the pain again and shot himself. The deaths are understated, because when a person goes into hospice or is unable to go out of the house, I recommend that the warfarin be stopped unless they have a mechanical heart valve. I do this because I see little reason to anticoagulate a person who is near death. There is a good chance that they will stop eating causing the INR to increase and possibly bleed. If they have accepterd that death is near, then I think that it would be less traumatic to have occur from an unseen cause rather than bleeding. In fact, bleeding would probably cause them to go to the hospital and die there which is probably what they did not want.
I hope this helps reassure some of the people who are worrying about warfarin.
We have had over 11,000 patient visits. There were just under 900 people involved. We had just about every reason that you could think of for taking warfarin. The ages ranged from 5 months to 107 years. So far we have reviewed about half os the charts and this is what we found.
At about 60% of the visits, the INR was in the desired range give or take 0.2 INR units.
There were about 460 patient years covered.
There was 1 episode of minor bleeding per patient year. In most studies, major bleeding is defined as life-threatening or requiring 2 units of blood to be transfused. We used this definition. Anything that required the person to stop what they were doing to attend to the bleeding up to a bleed that required 2 units of blood was defined as minor bleeding. For example, if someone blew their nose and there was a spot of blood on the handkerchief but no action was required, this did not constitute minor bleeding. But if someone woke up to find a spot of blood on the pillow case and they had to wash it, this was minor bleeding. Almost all minor bleeding was from the nose.
Clotting events occurred at the rate of 2 per 100 patient years. Most were minor clots in the legs. Most occurred when the INR was low when the person stopped warfarin. Most required no other treatment than re-starting warfarin.
There were 25 major events. These included strokes - both clotting and bleeding, one heart attack, gastrointestinal bleeds, bloody noses, etc. This is a rate of a little over 5 per 100 patient years. All but 4 of these events occurred in people who had serious conditions besides the one that caused them to be on warfarin. These conditions included being very frail, alcoholism, having heart failure caused by being hit by lightning, lupus, extreme anorexia causing the INR to be elevated at many visits etc. So when you look at people who had only one major condition, (heart valve, atrial fibrillation, uncomplicated blood clot in the leg etc) then major events - clotting or bleeding occurred less than once per 100 patient years.
There were three deaths - one was a suicide. That person had previously had a bleed into the knee joint and he felt it coming on again. He called a relative and said that he could not go through the pain again and shot himself. The deaths are understated, because when a person goes into hospice or is unable to go out of the house, I recommend that the warfarin be stopped unless they have a mechanical heart valve. I do this because I see little reason to anticoagulate a person who is near death. There is a good chance that they will stop eating causing the INR to increase and possibly bleed. If they have accepterd that death is near, then I think that it would be less traumatic to have occur from an unseen cause rather than bleeding. In fact, bleeding would probably cause them to go to the hospital and die there which is probably what they did not want.
I hope this helps reassure some of the people who are worrying about warfarin.
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