University of Oxford - Nuffield Department of Primary Care Health Sciences, University of Oxford - Nuffield Department of Primary Care Health Sciences, University of Oxford - Nuffield Department of Primary Care Health Sciences, University of Southampton, University of Oxford - Nuffield Department of Primary Care Health Sciences, University of Oxford - Nuffield Department of Primary Care Health Sciences, University of Oxford - Nuffield Department of Primary Care Health Sciences, University of Nottingham - Centre for Academic Primary Care, University of Cambridge - Department of Public Health and Primary Care, University of Leicester - Leicester Diabetes Centre, Queen Mary University of London, University of Leicester - Diabetes Research Centre and University of Toronto - Department of Medicine