1. Institute of Health and Society, Research Centre for Habilitation and Rehabilitation Models and Services (CHARM), Faculty of Medicine, University of Oslo, Oslo, Norway.
2. Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Oslo, Norway.
3. Institute of Health and Society, Department of Health Management and Health Economics, University of Oslo, Oslo, Norway.
4. Sunnaas Rehabilitation Hospital Trust, Nesoddtangen, Norway.
5. Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
6. Department of Family Medicine and Population Health, Division of Epidemiology, Virginia Commonwealth University, Richmond, Virginia.