From the *Section of Social Medicine, Institute of General Practice and Community Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; †National Resource Centre for Rehabilitation in Rheumatology, Diakonhjemmet Hospital, Oslo, Norway; ‡Health UMB, Research Group for Nature, Health and Quality of Life, Norwegian University of Life Sciences (UMB), Akershus, Norway; §Stress, Health and Rehabilitation, Unifob Helse, University of Bergen, Bergen, Norway; ¶FORMI (Communication Unit for Musculoskeletal Disorders), Division for Neuroscience and Musculoskeletal Medicine, Ullevaal University Hospital, Oslo, Norway; and ∥Section for Statistics and Research, Norwegian Directorate for Labour and Welfare, Oslo, Norway.
Acknowledgment date: July 5, 2009. First revision date: August 28, 2009. Second revision date: October 30, 2009. Third revision date: February 22, 2010. Acceptance date: April 19, 2010.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
The study has been approved by the Norwegian Regional Committee of Medical Ethics.
Address correspondence and reprint requests to Bård Natvig, MD, PhD, Institute of General Practice and Community Health, Faculty of Medicine, University of Oslo, P.O.Box 1130 Blindern, N-0318 Oslo, Norway; E-mail: [email protected]
