[1] Univ Iceland, Fac Med, Sturlugata 8, IS-101 Reykjavik, Iceland
[2] Univ Iceland, Ctr Publ Hlth Sci, Reykjavik, Iceland
[3] Skane Univ Hosp, Dept Hematol & Coagulat Disorders, Malmo, Sweden
[4] Karolinska Univ Hosp, Dept Med, Stockholm, Sweden
[5] Karolinska Inst, Stockholm, Sweden
[6] Mem Sloan Kettering Canc Ctr, Myeloma Serv, 1275 York Ave, New York, NY 10021 USA