[1] Univ British Columbia, Dept Med, Vancouver, BC, Canada
[2] Univ British Columbia, Dept Emergency Med, Vancouver, BC, Canada
[3] Providence Hlth Care, Vancouver, BC, Canada
[4] Univ Sherbrooke, Dept Med Familiale & Med Urgence, Sherbrooke, PQ, Canada
[5] Sinai Hlth, Schwartz Reisman Emergency Med Inst, Toronto, ON, Canada
[6] Univ Toronto, Temerty Fac Med, Dept Family & Community Med, Div Emergency Med, Toronto, ON, Canada
[7] Univ British Columbia, Dept Geriatr Med, 1081 Burrard St, Providence Bldg 9B, Vancouver, BC V6Z 1Y6, Canada