1. Centre for Behaviour Change, University College London, London, UK
2. Institute of Applied Health Sciences, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen, UK
3. Department of Psychology, University of Minnesota, Minneapolis, MN, USA
4. Radboud University Medical Center, Radboud Institute for Health Sciences, IQ Healthcare, Nijmegen, the Netherlands
5. Primary Care Unit, Cambridge Institute of Public Health, University of Cambridge, Cambridge, UK
6. Department of Kinesiology, College of Health Sciences, University of Rhode Island, Kingston, RI, USA
7. Department of Psychology, National University of Ireland Galway, Galway, Ireland
8. National Institute for Health Research (NIHR) Health Protection Research Unit in Behavioural Science and Evaluation, University of Bristol, Bristol, UK
9. National Advisory Unit on Rehabilitation in Rheumatology, Diakonhjemmet Hospital, Oslo, Norway