[1] Boston Med Ctr, Dept Emergency Med, Housestaff, BCD Bldg,1st Fl,800 Harrison Ave, Boston, MA 02118 USA
[2] Duke Univ, Sch Med, Dept Pediat, Dept Med, Durham, NC USA
[3] Duke Univ, Dept Populat Hlth, Sch Med, Durham, NC USA
[4] Duke Univ, Sch Nursing, Durham, NC USA
[5] Duke Univ, Sch Med, Dept Pediat, Durham, NC USA