University of Oslo, Oslo, Norway
Godthaab rehabilitation center, Bekkestua, Norway
Oslo University Hospital, Oslo, Norway
Akershus University Hospital, Lørenskog, Norway
University of Oslo, Oslo, Norway
University of Oslo, Oslo, Norway
Vestre Viken Hospital Trust, Bærum, Norway
Vestfold Hospital Trust, Tønsberg, Norway
St Olavs Hospital, Trondheim, Norway
University of Oslo, Oslo, Norway
Department of General Practice/General Practice Research Unit, Institute of Health and Society, University of Oslo, Oslo, Norway
Prestelokka Rehabilitation Centre, Stavern, Vestfold, Norway
Institute of Health and Society, Faculty of Medicine, University of Oslo, Oslo, Norway
Dental and Medical Faculty, University of Oslo, Oslo, Norway