[1] UCL, Dept Epidemiol & Publ Hlth, London WC1E 6BT, England
[2] Finnish Inst Occupat Hlth, Helsinki, Finland
[3] Univ Texas Sch Publ Hlth, Hlth Sci Ctr Houston, Div Environm & Occupat Hlth Sci, San Antonio, TX USA
[4] Inst Work & Hlth, Toronto, ON, Canada
[5] Univ Glasgow, UK MRC Social & Publ Hlth Sci Unit, Glasgow G12 8QQ, Lanark, Scotland
[6] Univ Edinburgh, Ctr Cognit Ageing & Cognit Epidemiol, Edinburgh EH8 9YL, Midlothian, Scotland
[7] Univ Helsinki, Dept Psychol, FIN-00014 Helsinki, Finland