Evaluation of antithrombotic usage for atrial fibrillation in aged care facilities

What is known and Objective: Warfarin is an important drug for the prevention of thromboembolic events such as stroke in patients with atrial fibrillation (AF). However, it is commonly implicated in major adverse drug events, which may result in reluctance to prescribe warfarin, especially in the institutionalised elderly population. This study aimed to assess the current trends in the antithrombotic management of AF in aged care facilities (ACFs) in Tasmania, Australia, and to compare this with current recommendations. Methods: We performed a non-experimental, retrospective cohort study designed to evaluate antithrombotic usage for AF in ACF residents in Tasmania. Residents with AF were identified on a patient-by-patient basis from residential case-note summaries collected from 29 of the 64 ACFs in Tasmania. The CHADS-2 score and the presence or absence of documented contraindications were used to determine the appropriateness of the current antithrombotic therapy prescribed. Results and Discussion: Fifteen per cent (262 ⁄ 1737) of the ACF residents were diagnosed with AF. Nine per cent of the residents with AF had a contraindication to antithrombotic therapy (either warfarin or antiplatelet therapy). Eightyone per cent of residents were eligible for treatment with warfarin according to the CHADS- 2 score and did not appear to have a contraindication to warfarin. Of these, only 38% were prescribed warfarin; 16% (40 ⁄ 255) did not receive any antithrombotic treatment, despite being eligible for treatment with warfarin or antiplatelet therapy. Residents who did not receive any antithrombotic treatment or who received antiplatelet treatment were significantly older than those treated with anticoagulants. What is new and Conclusion: Our results indicate that antithrombotic therapy, particularly warfarin, is underused in ACF-dwelling elderly patients who are eligible for treatment.