1. The Research Unit PROgrez, Department of Physiotherapy and Occupational Therapy, Næstved-Slagelse-Ringsted Hospitals, Region Zealand, Denmark
2. Department of Regional Health Research, University of Southern Denmark, Denmark
3. National Institute of Public Health, University of Southern Denmark, Denmark
4. Lolland-Falster Health Study, Centre for Epidemiological Research, Nykøbing Falster Hospital, Nykøbing F., Denmark
5. The Research Unit for General Practice and Section of General Practice, Institute of Public Health, University of Copenhagen, Copenhagen, Denmark
6. Research Unit for Musculoskeletal Function and Physiotherapy, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark