While my colleagues and I found that approximately 30% of elderly patients with atrial fibrillation residing in nursing homes were receiving treatment with warfarin, the information that was available did not allow for a determination of whether the level of treatment was too low, too high, or just right. Simply specifying a level of use for any medication as the "ideal," without taking into consideration individual patient characteristics, is a poor approach to assessing quality of care. However, in our article, we did raise specific concerns about the predominant pattern of underdosing of warfarin in the nursing home setting. On average, patients were maintained in a subtherapeutic range 44.8% of the time and in a supertherapeutic range 15.6% of the time.
Hylek and Singer1 did find that age was independently related to the occurrence of intracrancial hemorrhage in patients treated in an anticoagulant therapy unit (odds ratio, 1.4 per decade