1. Health Economics Unit, University of Birmingham, UK
2. Primary Care Unit, University of Cambridge, UK
3. Nuffield Department of Primary Care Health Sciences, University of Oxford, UK
4. School of Psychology, University of Central Lancashire, UK
5. Primary Care Clinical Sciences, University of Birmingham, UK
6. School of Medicine, University of Southampton, UK
7. Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Canada
8. School of Population and Public Health, University of British Columbia, Canada
9. Institute of Cardiovascular Sciences, University College London, UK