[1] Univ Otago, Christchurch Sch Med & Hlth Sci, Christchurch, New Zealand
[2] Univ Canterbury Te Whare Wananga Waita, Sch Hlth Sci, Christchurch, New Zealand
[3] Univ Queensland, Sch Clin Med, Primary Care Clin Unit, Brisbane, Qld, Australia
[4] Canterbury Dist Hlth Board, Christchurch, New Zealand
[5] Harvard Med Sch, Boston, MA 02115 USA
[6] Beth Israel Deaconess Med Ctr, Dept Med, Div Geriatr Med, Boston, MA USA
[7] Hebrew Senior Life, Boston, MA USA
[8] Yale Sch Publ Hlth, Dept Biostat, New Haven, CT USA
[9] Yale Univ, Sch Med, Dept Internal Med, New Haven, CT 06510 USA