1. Research and Knowledge Centre, The Danish Veterans Centre, Ringsted, Denmark
2. Section for Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
3. The Research Unit and Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
4. The Research Unit for General Practice and Section for General Medical Practice, Department of Public Health, Aarhus University, Aarhus, Denmark
5. Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospitals, Frederiksberg, Denmark