1. Cochrane Institute of Primary Care and Public Health, School of Medicine, Cardiff University, Cardiff, UK
2. Centre for Academic Primary Care, National Institute for Health Research School of Primary Care Research, School of Social and Community Medicine, University of Bristol, Bristol, UK
3. South East Wales Trials Unit, School of Medicine, Cardiff University, Cardiff, UK
4. Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
5. Swansea Centre for Health Economics, Swansea University, Swansea, UK
6. Population Health Sciences, School of Medicine, University of Dundee, Dundee, UK
7. Specialist Antimicrobial Chemotherapy Unit, Public Health Wales Microbiology Cardiff, University Hospital Wales, Cardiff, UK
8. Centre of Evidence Based Dermatology, University of Nottingham, Nottingham, UK
9. Park House Surgery, Surrey, UK
10. Department of Family and Community Medicine and Dalla Lana School of Public Health, North York General Hospital University of Toronto, Toronto, ON, Canada