1. Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, 751 85 Uppsala, Sweden
2. Department of Statistics, Uppsala University, 751 20 Uppsala, Sweden
3. Department of Medical Sciences, Uppsala University, 751 85 Uppsala, Sweden
4. Department of Global Public Health, Karolinska Institute, 171 77 Stockholm, Sweden
5. Department of Medical Sciences, Respiratory, Allergy and Sleep Research, Uppsala University, 751 85 Uppsala, Sweden
6. Department of Medical Sciences, Clinical Physiology, Uppsala University, 751 85 Uppsala, Sweden
7. Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University, 753 10 Uppsala, Sweden