1. Department of Clinical Sciences, Karolinska Institutet, and University Department of Rehabilitation Medicine Stockholm, Danderyd Hospital, SE-182 88 Stockholm, Sweden
2. Sandviken Hospital and Uppsala University, Sweden
3. Centre for Research and Development, Uppsala University/County Council of Gävleborg Gävle, Sweden
4. Department of Community Medicine and Rehabilitation, Rehabilitation Medicine, Umeå University, Umeå, Sweden
5. Formerly of Department of Rehabilitation Medicine, University Hospital Uppsala and Uppsala University, Sweden