作者单位:RAND, Santa Monica, CA USA[1]Boston Childrens Hosp, Div Gen Pediat, Boston, MA USA[2]NYU, Sch Med, Dept Med, New York, NY USA[3]Univ Texas Hlth Sci Ctr Houston, Houston, TX 77030 USA[4]Univ Alabama Birmingham, Dept Psychol, Birmingham, AL 35294 USA[5]