[1] Otago Polytech, Sch Occupat Therapy, Dunedin, New Zealand
[2] Univ Otago, Dunedin Sch Med, Dept Prevent & Social Med, Dunedin, New Zealand
[3] Univ Michigan, Transportat Res Inst, Ann Arbor, MI 48109 USA
[4] Univ Auckland, Fac Med & Hlth Sci, Sch Populat Hlth, Auckland, New Zealand
[5] Univ Auckland, Freemasons Dept Geriatr Med, Auckland, New Zealand
[6] Waitemata Dist Hlth Board, Auckland, New Zealand