1. Centre for Academic Primary Care, National Institute for Health Research (NIHR) School for Primary Care Research, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, England
2. Primary Care and Population Science, NIHR School for Primary Care Research, Faculty of Medicine, University of Southampton, Aldermoor Health Center, Southampton, England
3. Nuffield Department of Primary Care Health Sciences, NIHR School for Primary Care Research, University of Oxford, Oxford, England
4. Department of Family Medicine, University of Washington, Seattle
5. Division of Primary Care, NIHR School for Primary Care Research, School of Medicine, University of Nottingham, Nottingham, England
6. Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, England
7. Bristol Randomised Trials Collaboration, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, England
8. Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, England