[1] UiT, Dept Clin Med, KG Jebsen Thrombosis Res & Expertise Ctr, Tromso, Norway
[2] Univ Calif San Diego, La Jolla, CA 92093 USA
[3] UiT, Dept Community Med, Tromso, Norway
[4] UiT, Dept Clin Med, Brain & Circulat Res Grp, Tromso, Norway
[5] Leiden Univ, Med Ctr, Dept Clin Epidemiol, Leiden, Netherlands
[6] Univ Hosp North Norway, Div Internal Med, Tromso, Norway