1. Centre for Clinical and Community Applications of Health Psychology, Faculty of Environmental and Life Sciences, University of Southampton , Southampton , UK
2. Centre of Evidence Based Dermatology, Lifespan and Population Health, School of Medicine, University of Nottingham , Nottingham , UK
3. Primary Care Research Centre, Primary Care, Population Sciences and Medical Education Unit, Faculty of Medicine, University of Southampton , Southampton , UK
4. Population Health Sciences, University of Bristol , Bristol , UK
5. Department of Dermatology, Rotherham NHS Foundation Trust , Rotherham , UK
6. Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine , London , UK
7. Southampton Clinical Trials Unit, University of Southampton , UK
8. Health Economics Group, Norwich Medical School, University of East Anglia, Norwich Research Park , Norwich , UK
9. School of Psychological Science, University of Bristol , Bristol , UK