[1] Queen Mary Univ London, Canc Res UK Ctr Epidemiol Math & Stat, Wolfson Inst Prevent Med, London EC1M 6BQ, England
[2] London Sch Hyg & Trop Med, Noncommunicable Dis Epidemiol Unit, London WC1, England
[3] Thames Stroke Res Network, London, England
[4] Cent Manchester Univ NHS Fdn Trust, Manchester Cytol Ctr, Manchester, Lancs, England
[5] Univ Manchester, Sch Canc & Imaging Sci, Manchester, Lancs, England