An Investigation of the Management of the International Normalised Ratio (INR) in Warfarin Therapy During the Initial Five Months of Treatment

Abstract

The clinical effectiveness of warfarin as an anticoagulant in the primary and secondary prevention and treatment of thromboembolic disease has long been established. With the advent of anticoagulant treatment for atrial fibrillation, the number of patients receiving warfarin therapy has dramatically increased. Conversely, warfarin is a potentially hazardous drug with research indicating that patients are at the greatest risk of bleeding during the first three months of treatment and that anticoagulants have undergone the greatest increase in adverse drug reactions in Australia since 1981, revealing that this is a highly prevalent, costly process that will continue to grow in the future. Therefore, this study investigated the current process of management of warfarin therapy through the hospital/community interface from initiation for a period of five months, or less if warfarin therapy was ceased prior to this time. It was anticipated that this study would clarify unresolved key issues of warfarin therapy during this time in order to improve clinical outcomes and consequently reduce costs.