[1] Sunnybrook Hlth Sci Ctr, Dept Anesthesia, Toronto, ON, Canada
[2] Univ Toronto, Dept Anesthesia, 123 Edward St,12th Floor,Suite 1201, Toronto, ON M5G 1E2, Canada
[3] Queens Univ, Dept Family Med, Kingston, ON, Canada
[4] Univ British Columbia, Dept Family Med, Bella Bella, BC, Canada
[5] Flinders Univ S Australia, Royal Darwin Hosp, Dept Anaesthesia & Perioperat Med, Darwin, NT, Australia
[6] West Virginia Univ, Dept Anesthesiol, Morgantown, WV 26506 USA
[7] Mem Univ, Discipline Family Med, Fac Med, St John, NF, Canada
[8] Univ Toronto, Dept Family & Community Med, Toronto, ON, Canada
[9] McMaster Univ, Dept Anesthesia & Pain Med, Hamilton, ON, Canada
[10] Univ Alberta, Dept Anesthesiol & Pain Med, Edmonton, AB, Canada