1. Centre of Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
2. Department of Respiratory Medicine, Landspitali University Hospital, Reykjavik, Iceland
3. Clinical Epidemiology and Biostatistics, School of Medical Sciences, Örebro University, Örebro, Sweden
4. Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
5. Department of Immunology, Genetics and Pathology, Clinical and Experimental Pathology, Uppsala University, Uppsala, Sweden
6. Department of Medical Sciences, Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden
7. Department of Clinical Chemistry, Landspitali University Hospital, Reykjavik, Iceland
8. Department of Psychology, Reykjavik University, Reykjavik, Iceland
9. Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, USA
10. Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
11. Department of Psychological and Brain Sciences, University of Iowa, Iowa City, Iowa, USA
12. Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA