1. University of Birmingham; Institute of Applied Health Research; Birmingham UK B15 2TT
2. Newcastle Hospitals NHS Trust, Royal Victoria Infirmary; Newcastle Hospitals; Newcastle UK
3. University of Leeds; Section of Epidemiology and Biostatistics; St James's Hospital Leeds UK LS9 7TF
4. Dudley Hospitals Foundation Trust, Corbett Hospital; Department of Dermatology; Wicarage Road Stourbridge UK DY8 4JB
5. Mount Vernon Hospital; Mount Vernon Cancer Centre; Rickmansworth Road Northwood UK HA6 2RN
6. Churchill Hospital; Department of Dermatology; Old Road Headington Oxford UK OX3 7LJ
7. The University of Nottingham; c/o Cochrane Skin Group; Nottingham UK
8. The University of Nottingham; Centre of Evidence Based Dermatology; Queen's Medical Centre Derby Road Nottingham UK NG7 2UH