[1] IDIAP Jordi Gol Primary Care Res Inst, Barcelona, Spain
[2] FIMIM Inst Salud Carlos III, URFOA, Barcelona, Spain
[3] FIMIM Inst Salud Carlos III, RETICEF, Barcelona, Spain
[4] Univ Southampton, MRC Lifecourse Epidemiol Unit, Southampton, Hants, England
[5] Univ Oxford, NDORMS, Oxford, England
[6] Royal N Shore Hosp, Kolling Inst Med Res, Inst Bone & Joint Res, Sydney, NSW, Australia