Hemorrhagic complications of oral anticoagulant therapy.

Hemorrhage is the major complication of anticoagulant therapy. The criteria for classifying the severity of bleeding has varied between studies, which has resulted in variability in the rate of bleeding reported in the literature. The major determinants of oral anticoagulant-related bleeding are the intensity of the anticoagulant effect, baseline patient characteristics, and the length of therapy. Older patients have characteristics that may place them at higher risk for anticoagulant-related bleeding, but they also have characteristics that make them more likely to benefit. The risk for anticoagulant-related bleeding cannot be considered in isolation and the potential benefits need to be weighed carefully in each individual patient, irregardless of age.