[1] Silkeborg Reg Hosp, Univ Clin Dev Innovat Patient Pathways, Diagnost Ctr, Falkevej 3, DK-8600 Silkeborg, Denmark
[2] Aarhus Univ, Dept Clin Med, Aarhus, Denmark
[3] Aalborg Univ, Dept Clin Med, Danish Ctr Clin Hlth Serv Res, Aalborg, Denmark
[4] Univ Liverpool, Liverpool Ctr Cardiovasc Sci, Liverpool, Merseyside, England
[5] Liverpool Heart & Chest Hosp, Liverpool, Merseyside, England
[6] Tufts Univ, Tufts Clin & Translat Sci Inst, Boston, MA 02111 USA
[7] Tufts Med Ctr, Inst Clin Res & Hlth Policy Studies, Boston, MA 02111 USA
[8] Boston Univ, Sch Publ Hlth, Dept Biostat, Boston, MA USA
[9] Aalborg Univ, Dept Clin Med, Aalborg, Denmark