1. Centre for Academic Child Health, University of Bristol, Bristol Medical School, Bristol, UK
2. Bristol Trials Centre (Bristol Randomised Trials Collaboration), Bristol Medical School, Department of Population Health Sciences, University of Bristol, Bristol, UK
3. Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Primary Care Building, Oxford, UK
4. Centre for Academic Primary Care, Bristol Medical School, Population Health Sciences, University of Bristol, Bristol, UK
5. School for Policy Studies, University of Bristol, Bristol, UK
6. Primary Care and Population Sciences, University of Southampton, Aldermoor Health Centre, Southampton, UK
7. NHS England and NHS Improvement, South West, UK
8. School of Population Health and Environmental Sciences, King’s College London, London, UK