n CLINICAL n © Managed Care &

Approximately 4 million people in the United States receive oral anticoagulation therapy with the vitamin K antagonist (VKA) warfarin,1 and require frequent international normal-ized ratio (INR) monitoring to maintain time in the therapeutic range.2 There are several models of warfarin management designed to maintain the patients ’ INR within these desired parameters.3 These include usual care (UC), which means an individual physician manages multiple pa-tients without formal systematic monitoring policies or procedures to focus on dose management; anticoagulation clinic care (AC), which means dose management is overseen by a healthcare provider (usually a nurse or pharmacist) under physician leadership with systematic poli-cies and procedures in place; and patient self-testing (PST) or patient self-management (PSM), which means patients perform their own INR test at home with a portable point-of-care (POC) instrument and re-ceive dose instructions from a healthcare provider (PST) or manage their own dose (PSM). Under UC or AC, test frequency may be irregu-lar, and is often determined by a patient’s ability to travel to a lab o