1. Department of Cardiology, Østfold Hospital Trust, PO Box 300, 1714 Grålum, Sarpsborg, Norway
2. Institute of Clinical Medicine, University of Oslo, PO Box 1171 Blindern, 0318 Oslo, Norway
3. HUNT Research Centre, Faculty of Medicine and Health Sciences, NTNU—Norwegian University of Science and Technology, Forskningsveien 2, 7600 Levanger, Norway
4. Department of Haematology, Østfold Hospital Trust, PO Box 300, 1714 Grålum. Sarpsborg, Norway
5. Statisticon AB, Klara Södra kyrkogata 1, 111 52 Stockholm, Sweden
6. Department of Cardiology, Oslo University Hospital Ullevål, PO Box 4956, Nydalen. NO-0424 Oslo, Norway