Open Access Study protocol

A randomized trial to assess the impact of an antithrombotic decision aid in patients with nonvalvular atrial fibrillation: the DAAFI trial protocol [ISRCTN14429643]

Finlay A McAlister1*, Malcolm Man-Son-Hing2, Sharon E Straus3, William A Ghali4, Paul Gibson4, David Anderson5, Jafna Cox5, Miriam Fradette6 and the Decision Aids in Atrial Fibrillation (DAAFI) Investigators

Author Affiliations

1 The Division of General Internal Medicine, University of Alberta, Edmonton, Canada

2 Elisabeth Bruyere Research Institute and Geriatric Medicine, University of Ottawa, Ottawa, Canada

3 The Divisions of Geriatric and General Internal Medicine, University of Toronto, Toronto, Canada

4 General Internal Medicine, University of Calgary, Calgary, Canada

5 Department of Medicine, Dalhousie University and Capital Health, Halifax, Canada

6 The Epidemiology Coordinating and Research Centre, University of Alberta, Edmonton, Canada

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BMC Cardiovascular Disorders 2004, 4:5  doi:10.1186/1471-2261-4-5

Published: 5 May 2004



Decision aids are often advocated as a means to assist patient and health care provider decision making when faced with complicated treatment or screening decisions. Despite an exponential growth in the availability of decision aids in recent years, their impact on long-term treatment decisions and patient adherence is uncertain due to a paucity of rigorous studies. The choice of antithrombotic therapy for nonvalvular atrial fibrillation (NVAF) is one condition for which a trade-off exists between the potential risks and benefits of competing therapies, and the need to involve patients in decision making has been clearly identified. This study will evaluate whether an evidence-based patient decision aid for patients with NVAF can improve the appropriateness of antithrombotic therapy use by patients and their family physicians.


A multi-center, two-armed cluster randomized trial based in community family practices in which patients with NVAF will be randomized to decision aid or usual care. Patients will receive one of four decision aids depending on their baseline stroke risk. The primary outcome is the provision of "appropriate antithrombotic therapy" at 3 months to study participants (appropriateness defined as per the 2001 American College of Chest Physicians recommendations for NVAF). In addition, the impact of this decision aid on patient knowledge, decisional conflict, well-being, and adherence will be assessed after 3 months, 6 months, and 12 months.