[1] Univ British Columbia, Sch Nursing, Vancouver, BC V6T 2B5, Canada
[2] Univ British Columbia, Div Adolescent Med, Dept Pediat, Vancouver, BC V6T 2B5, Canada
[3] McCreary Ctr Soc, Vancouver, BC, Canada
[4] Univ Minnesota, Sch Nursing, Minneapolis, MN 55455 USA
[5] Publ Hlth Seattle & King Cty, Washington, DC USA