1. Center for General Practice (M.V.F., J.K.K., M.B.J.), Aalborg University, Denmark.
2. Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Faculty of Health (P.B.N., T.B.L., T.F.O., G.Y.H.L.), Aalborg University, Denmark.
3. Department of Cardiology, Atrial Fibrillation Study Group, Aalborg University Hospital, Denmark (P.B.N., T.B.L.).
4. Department of Medicine, North Denmark Regional Hospital, Hjørring, Denmark (T.F.O.).
5. Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart and Chest Hospital, United Kingdom (G.Y.H.L.).