1. Primary Care Unit, Department of Public Health & Primary Care, University of Cambridge , Cambridge CB2 0SR , UK
2. Division of Population Health, Health Services Research and Primary Care, School of Health Sciences, University of Manchester , Oxford Rd, Manchester M13 9PL , UK
3. The Healthcare Improvement Studies Institute, University of Cambridge , Clifford Allbutt Building Cambridge Biomedical Campus, Cambridge CB2 0AH , UK
4. Faculty of Medicine and Health Sciences, Keele University , David Weatherall Building, Keele ST5 5BG , UK
5. Centre for Research in Public Health and Community Care, University of Hertfordshire , Hatfield Hertfordshire AL10 9AB , UK
6. Patient Collaborator
7. Division of Nursing, Midwifery & Social Work, School of Health Sciences, University of Manchester , Oxford Rd, Manchester M13 9PL , UK