[1] Dalhousie Univ, Fac Hlth, Halifax, NS, Canada
[2] IWK Hlth Ctr, Ctr Pediat Pain Res, Halifax, NS, Canada
[3] Dalhousie Univ, Dept Psychol & Neurosci, 5850-5980 Univ Ave, Halifax, NS, Canada
[4] Dalhousie Univ, Dept Pediat, Halifax, NS, Canada
[5] Hosp Sick Children, SickKids Res Inst, Child Hlth Evaluat Sci, Toronto, ON, Canada
[6] Univ Toronto, Fac Med, Toronto, ON, Canada
[7] Univ Toronto, Dalla Lana Sch Publ Hlth, Toronto, ON, Canada
[8] Dalhousie Univ, WK Kellogg Hlth Sci Lib, Halifax, NS, Canada
[9] Univ Ottawa, Dept Pediat, Fac Med, Ottawa, ON, Canada
[10] Univ Ottawa, Sch Epidemiol & Publ Hlth, Fac Med, Ottawa, ON, Canada
[11] Univ Calif San Francisco, Dept Anesthesia & Perioperat Care, San Francisco, CA 94143 USA
[12] Laval Univ, Fac Med, Dept Family & Emergency Med, Quebec City, PQ, Canada
[13] Laval Univ, Fac Med, Off Educ & Profess Dev, Quebec City, PQ, Canada
[14] Univ Laval, CHU Quebec, Quebec City, PQ, Canada
[15] Ottawa Hosp, Res Inst, Ottawa, ON, Canada