[1] UNIV CALGARY, FAC MED,DEPT MED,DEPT PHARMACOL & THERAPEUT, DIV INTERNAL MED, CALGARY T2N 1N4, ALBERTA, CANADA
[2] MEM UNIV NEWFOUNDLAND, FAC MED, DIV BASIC MED SCI, St John A1B 3V6, NEWFOUNDLAND, CANADA
[3] MEM UNIV NEWFOUNDLAND, FAC MED, DIV COMMUNITY MED, St John A1C 5S7, NEWFOUNDLAND, CANADA
[4] UNIV CALGARY, FAC MED,DEPT MED,DEPT PHARMACOL & THERAPEUT, DIV GERIATR, CALGARY T2N 1N4, ALBERTA, CANADA