[1] Seattle Childrens Res Inst, Ctr Child Hlth Behav & Dev, Seattle, WA USA
[2] Oregon Hlth & Sci Univ OHSU, Dept Pediat, Div Psychol, Portland, OR USA
[3] Univ Washington, Dept Anesthesiol & Pain Med, Sch Med, Seattle, WA USA
[4] Harvard Med Sch, Brigham & Womens Hosp, Dept Anesthesiol Perioperat & Pain Med, Boston, MA USA
[5] Seattle Childrens Res Inst, Ctr Clin & Translat Res, Seattle, WA USA
[6] Univ Washington, Dept Anesthesiol & Pain Med, Sch Med, 4800 Sand Point Way NE,MB11 500-3, Seattle, WA 98105 USA