1. Wolfson Institute of Population Health, Queen Mary University of London, London, E1 4NS, UK
2. School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
3. Centre for Ethics in Medicine, Population Health Sciences, Bristol Medical School, Bristol, BS8 2PS, UK
4. Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, OX2 6GG, UK
5. School of Law, Politics and Sociology, University of Sussex, Brighton, BN1 9QE, UK