[1] CNR, Inst Neurosci Aging Branch, Via Giustiniani 2, I-35128 Padua, Italy
[2] Univ Oxford, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, Oxford, England
[3] South London & Maudsley NHS Fdn Trust, Physiotherapy Dept, London, England
[4] Kings Coll London, Dept Psychol Med, London, England
[5] Univ Padua, Dept Med, Padua, Italy
[6] Univ Southampton, Southampton Gen Hosp, MRC Lifecourse Epidemiol Unit, Southampton, Hants, England
[7] Vrije Univ Amsterdam, Med Ctr, Amsterdam Publ Hlth Res Inst, Dept Epidemiol & Biostat,Amsterdam UMC, Amsterdam, Netherlands
[8] Vrije Univ Amsterdam, Fac Sci, Dept Hlth Sci, Amsterdam, Netherlands
[9] Univ Ulm, Inst Epidemiol & Med Biometry, Geriatr Res Unit, AGAPLESION Bethesda Hosp, Ulm, Germany
[10] Ulm Univ, Inst Hist Philosophy & Eth Med, Ulm, Germany
[11] Simon Fraser Univ, Dept Gerontol, Vancouver, BC, Canada
[12] Univ Autonoma Madrid, Fac Med, Unit Primary Care & Family Med, Dept Prevent Med & Publ Hlth, Madrid, Spain
[13] Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden