[1] UCL, Inst Epidemiol & Healthcare, Dept Behav Sci & Hlth, London, England
[2] UCL, Res Dept Clin Educ & Hlth Psychol, London, England
[3] Kings Coll London, Dept Psychol Med, London, England
[4] Publ Hlth England, Behav Sci Team, Emergency Response Dept Sci & Technol, Salisbury, Wilts, England