[1] Landspitali, Dept Internal Med, Reykjavik, Iceland
[2] Univ Iceland, Fac Med, Reykjavik, Iceland
[3] Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden
[4] Mem Sloan Kettering Canc Ctr, Div Hematol Oncol, Myeloma Serv, 1275 York Ave, New York, NY 10021 USA
[5] Sahlgrens Univ Hosp, Hematol Sect, Dept Internal Med, Gothenburg, Sweden
[6] Karolinska Univ Hosp, Dept Med, Div Hematol, Stockholm, Sweden
[7] Karolinska Inst, Stockholm, Sweden
[8] Skane Univ Hosp, Dept Hematol & Coagulat Disorders, Malmo, Sweden