1. DEFACTUM, Corporate Quality, Central Denmark Region, Aarhus, Denmark
2. Spine Center, Diagnostic Center, Silkeborg Regional Hospital, Silkeborg, Denmark
3. Department of Public Health, Aarhus University, Aarhus, Denmark
4. Department of Social Affairs and Employment, Aarhus Municipality, Aarhus, Denmark
5. Department of Clinical Social Medicine & Rehabilitation, Gødstrup Hospital, Aarhus, Denmark