1Department of Psychology, Faculty of Health, York University, 508 Atkinson, 4700 Keele Street, Toronto, Ont., Canada M3J 1P3
2Faculties of Nursing and Medicine, University of Toronto, Signy Hildur Eaton Chair in Paediatric Nursing Research and Associate Chief Nursing, The Hospital for Sick Children, 555 University Avenue, Room 4734b Toronto, Ont., Canada M5G 1X8
*Corresponding author. Tel.: +1 416 736 2100; fax: +1 416 736 5662.