[1] UCL, Dept Epidemiol & Publ Hlth, London, England
[2] Univ Cambridge, Dept Publ Hlth & Primary Care, Cambridge, England
[3] Univ Edinburgh, Ctr Cognit Ageing & Cognit Epidemiol, Edinburgh, Midlothian, Scotland
[4] Univ Southampton, MRC Lifecourse Epidemiol Unit, Southampton, Hants, England
[5] Univ Glasgow, MRC CSO Social & Publ Hlth Sci Unit, Glasgow, Lanark, Scotland
[6] Univ Bristol, Sch Social & Community Med, Bristol, Avon, England
[7] Univ Hosp Bristol NHS Fdn Trust, Natl Inst Hlth Res, Biomed Res Ctr, Bristol, Avon, England