Because management of long-term oral anticoagulant
therapy with vitamin K antagonists requires frequent testing
(measurement of the international normalized ratio
[INR]) and dose adjustment, anticoagulation clinics were
developed to streamline and standardize this care (1, 5).
Recently, portable devices have become available that
can measure the INR with a drop of capillary blood. Several
battery-operated models, including CoaguChek (F.