Summary of HALCyon cohorts.

<p>*For those participants with a date of birth provided (95 participants were aged 90 or over at baseline and their dates of birth are not recorded).</p><p>†Approximate size of sample at time that outcome measures for the HALCyon project were ascertained.</p><p>Note: LBC1921  =  Lothian Birth Cohort 1921; HAS  =  Hertfordshire Ageing Study; HCS  =  Hertfordshire Cohort Study; CaPS  =  Caerphilly Prospective Study; ABC1936  =  Aberdeen Birth Cohort 1936; ELSA  =  English Longitudinal Study of Ageing; NSHD  =  MRC National Survey of Health and Development (1946 British birth cohort); NCDS  =  National Child Development Study (1958 British birth cohort).</p><p>For description of sample please see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0027899#pone.0027899.s002" target="_blank">table S1</a>.</p>