Ruzan Udumyan1, Scott Montgomery2,3,4, Fang Fang5, Unnur Valdimarsdottir5,6,7, Hronn Hardardottir6,8, Anders Ekbom3, Karin E Smedby3,9, Katja Fall2,5. 1. Clinical Epidemiology and Biostatistics, School of Medical Sciences, Örebro University, Örebro, Sweden. Ruzan.Udumyan@oru.se. 2. Clinical Epidemiology and Biostatistics, School of Medical Sciences, Örebro University, Örebro, Sweden. 3. Division of Clinical Epidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden. 4. Department of Epidemiology and Public Health, University College London, London, United Kingdom. 5. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. 6. Center of Public Health Sciences, University of Iceland, Reykjavik, Iceland. 7. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts. 8. Department of Respiratory Medicine, Landspitali University Hospital, Reykjavik, Iceland. 9. Hematology Clinic, Karolinska University Hospital, Stockholm, Sweden.