1 Population Health Research Institute, St. George's University of London, London, UK.
2 Institute of Social Marketing and Health, University of Stirling, Stirling, UK.
3 School of Health and Psychological Sciences, City, University of London, London, UK.
4 Unit for Paediatric and Population-Based Dermatology Research, St John's Institute of Dermatology, Guy's & St Thomas' NHS Foundation Trust and King's College London, London, UK.
5 Nottingham Support Group for Carers of Children with Eczema, Nottingham, UK.
6 Imperial Clinical Trials Unit, School of Public Health, Imperial College, London, UK.
7 National Heart and Lung Institute, Imperial College London, London, UK.