[1] UCL, Res Dept Epidemiol & Publ Hlth, 1-19 Torrington Pl, London WC1E 7HB, England
[2] Univ Cambridge, British Heart Fdn Cardiovasc Epidemiol Unit, Strangeways Res Lab, Dept Publ Hlth & Primary Care, Cambridge, England
[3] Univ Cambridge, Natl Inst Hlth Res, Strangeways Res Lab, Blood & Transplant Unit Donor Hlth & Genom, Cambridge, England
[4] Cambridge Biomed Campus, Dept Clin Neurosci, Stroke Res Grp, Cambridge, England