[1] Free Univ Brussels, Dept Orthopaed & Traumatol, Acad Ziekenhuis, B-1090 Brussels, Belgium
[2] European Inst Oncol, Div Epidemiol & Biostat, Milan, Italy
[3] Grand Duchy Luxemburg, Ctr Res Epidemiol & Hlth Informat Syst Luxemburg, Luxembourg, Luxembourg
[4] Katholieke Univ Leuven, Univ Hosp Leuven, Div Geriatr Med, Louvain, Belgium
[5] Katholieke Univ Leuven, Ctr Metab Bone Dis, Louvain, Belgium
[6] Katholieke Univ Leuven, Univ Hosp Leuven, Div Geriatr Med, Dept Internal Med, Louvain, Belgium