PCV11: COST OF WARFARIN TREATMENT OF ATRIAL FIBRILLATION IN CLINICAL PRACTICE

Abstract

OBJECTIVES: Trials of anticoagulation in non-rheumatic atrial fibrillation have demonstrated a reduction in the risk of stroke by two-thirds. In these trials, the safety of anticoagulation appeared good, but this may be related to highly selected patient groups. Exclusion rates of 93% were reported. Participants may have had fewer complications than might be expected among less selected patients in clinical practice. No trials had actually looked at the costs of anticoagulation in a real day-to-day clinical practice. The aim of this study is to investigate the actual cost of warfarin treatment of atrial fibrillation in a real clinical practice. METHODS: A one-year retrospective study involving patients of all ages admitted to hospital with non-rheumatic atrial fibrillation on long-term oral anticoagulation. Patients were interviewed and their medical records reviewed. The costs of anticoagulation were viewed as follows: 1. The cost of the active drug. 2. The cost of monitoring the patient's INR i.e. traveling costs, staffing cost, and analysis costs. 3. The costs associated with bleeding complications. RESULTS: We studied 139 patients. The mean (SD) age was 73.6 (8.9) years, ranging from 41 to 93 years. The mean duration of oral anticoagulant therapy was 36 months (range 2 to 105 months), forming a total of 417 patient-years of treatment. Mean (SD) INR was 2.5 (0.36). The target range of 2.0–3.0 was achieved 54% of the time. Bleeding occurred in 21 patients, with incidence of 7.2% per patient-year for minor bleeding, 2.4% per patient-year for major bleeding and 0.2% for fatal bleeding. The cost of warfarin tablets was £14.6 ($23.36), per patient-year, but was £262.6 ($420.16), per patient-year after considering monitoring and bleeding complication costs. The cost per stroke prevented was estimated at £8,141 ($13,026). CONCLUSION: Anticoagulation appeared safe and cost-effective in clinical practice but control was not as good as in clinical trials.