[1] Univ Nottingham Hosp, Nottingham, England
[2] Univ Nottingham, Nottingham NG7 2RD, England
[3] Univ So Denmark, Copenhagen, Denmark
[4] Univ Wisconsin, Sch Med & Publ Hlth, Madison, WI USA
[5] Univ Louvain, Div Gerontol & Geriatr, Louvain, Belgium
[6] Harvard Univ, Sch Med, Inst Aging Res, Boston, MA USA
[7] Harvard Univ, Sch Med, Beth Israel Deaconess Med Ctr, Boston, MA USA