[1] UCL, London, England
[2] Homerton Univ Hosp, London, England
[3] Univ Coll London Hosp, London, England
[4] Royal Brompton Hosp, London, England
[5] Barts & London Queen Marys Sch Med & Dent, Wolfson Inst Prevent Med, London, England
[6] Nottingham Univ Hosp, David Evans Res Ctr, Nottingham, England