[1] Univ Manchester, Fac Biol Med & Hlth, Manchester M13 9PL, Lancs, England
[2] Salford Royal NHS Fdn Trust, Greater Manchester Comprehens Stroke Ctr, Manchester Acad Hlth Sci Ctr, Salford M6 8HD, Lancs, England
[3] Univ Manchester, Ctr Biostat, Manchester Acad Hlth Sci Ctr, Oxford Rd, Manchester, Lancs, England
[4] Univ Aberdeen, Inst Appl Hlth Sci, Sch Med Med Sci & Nutr, Room 4-013,Polwarth Bldg,Foresterhill, Aberdeen AB25 2ZD, Scotland
[5] Univ East Anglia, Norwich Med Sch, Norwich NR4 7TJ, Norfolk, England
[6] Norwich Cardiovasc Res Grp, Stroke Res Grp, Norwich Res Pk, Norwich NR4 7TJ, Norfolk, England
[7] Norfolk & Norwich Univ Hosp NHS Fdn Trust, Stroke Serv, Norwich NR4 7UY, Norfolk, England