[1] SUNY Buffalo, Sch Med & Biomed Sci, Dept Social & Prevent Med, Buffalo, NY 14214 USA
[2] SUNY Buffalo, Sch Med & Biomed Sci, Robert Warner Rehabil Ctr, Dept Pediat, Buffalo, NY 14214 USA
[3] Brown Univ, Sch Med, Rhode Isl Hosp, Child Dev Ctr,Dept Pediat, Providence, RI 02912 USA
[4] Harvard Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA 02115 USA