1. Nuffield Department of Primary Care Health Sciences, University of Oxford, United Kingdom
2. Centre for Academic Primary Care, NIHR School for Primary Care Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
3. Primary Care and Population Sciences, University of Southampton, Aldermoor Health Centre, Aldermoor Close, Southampton, United Kingdom
4. Department of Family Medicine, University of Washington, Seattle
5. Nuffield Department of Population Health, University of Oxford, United Kingdom