[1] Spital Netz Bern Ziegler, Univ Dept Geriatr, CH-3001 Bern, Switzerland
[2] Inselspital Univ Bern Hosp, Dept Geriatr, Bern, Switzerland
[3] Univ Bern, Inst Social & Prevent Med, CH-3012 Bern, Switzerland
[4] Univ Hamburg, Albertinen Haus Geriatr Ctr, Hamburg, Germany
[5] UCL, Dept Primary Care & Populat Sci, London WC1E 6BT, England
[6] Univ Calif Los Angeles, Sch Med, Los Angeles, CA USA
[7] Langley Res Inst, Pacific Palisades, CA USA