1. Nuffield Department of Primary Care Health Sciences, NIHR School for Primary Care Research, University of Oxford, Radcliffe Observatory Quarter, Oxford, UK;
2. Primary Care Research Group, University of Exeter Medical School, Smeall Building, St Luke’s Campus, Exeter, UK;
3. WMS—Social Science and Systems in Health, University of Warwick, Coventry, Birmingham, UK;
4. Institute of Applied Health Research, University of Birmingham, Edgbaston, Birmingham, UK;
5. Institute of Clinical Science, University of Birmingham, Edgbaston, Birmingham, UK;
6. NIHR Clinical Research Network: West Midlands, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK;
7. Primary Care Unit, Department of Public Health and Primary Care, University of Cambridge, Strangeways Research Laboratory, Wort’s Causeway, Cambridge, Cambridgeshire, UK;
8. School of Health Studies, University of Bradford, Bradford, UK.