1. Department of Surgical Sciences, Section of Orthopaedics; Uppsala University; Uppsala Sweden
2. Uppsala Clinical Research Center; Uppsala University; Uppsala Sweden
3. Department of Community Medicine and Rehabilitation, Section of Geriatric Medicine; Umeå University; Umeå Sweden
4. Department of Community Medicine and Rehabilitation, Section of Rehabilitation Medicine; Umeå University; Umeå Sweden
5. King's College, London; School of Medicine, Division of Cancer Studies; London UK
6. Department of Medical Epidemiology and Biostatistics; Karolinska Institutet; Stockholm Sweden
7. Department of Medical Sciences, Section of Clinical Pharmacology; Uppsala University; Uppsala Sweden