1. The Research Clinic for Functional Disorders, Aarhus University Hospital , Palle Juul Jensens Boulevard 11, 8200 , Aarhus N , Denmark
2. Institute of Clinical Medicine, Aarhus University , Aarhus N , Denmark
3. Centre for Clinical Research and Prevention, Bispebjerg/Frederiksberg Hospital, Capital Region , Copenhagen , Denmark
4. Department of Public Health, Faculty of Health and Medical Sciences, Copenhagen University , Copenhagen , Denmark
5. Faculty of Medicine, Aalborg University , Aalborg , Denmark