Measuring and Improving the Quality of Oral Anticoagulation for Veterans

More than 150,000 VHA patients receive oral anticoagulants each year to treat or prevent blood clots and related disorders.(1) The most commonly used anticoagulant in the VA system is warfarin, a vitamin K antagonist. Warfarin is challenging to manage well: It has a narrow therapeutic window, changes in dose require about 5 days to achieve the full effect, and warfarin's effect is modified by numerous interactions with diet, other drugs, and health status.(2) For this reason, warfarin requires frequent monitoring to keep patients within the desired therapeutic range.(2)