1. Department of Medical Sciences, Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden;
2. Department of Surgical Sciences, Orthopaedics, Uppsala University, Uppsala, Sweden;
3. Department of Health Sciences, Division of Geriatric Medicine, Lund University, Sweden and CRC, Skåne University Hospital, Malmö, Sweden;
4. Department of Medical Sciences, Cardiovascular Epidemiology, Uppsala University, Uppsala, Sweden