[1] Univ Calif Davis, Sch Med, Dept Pediat, 2516 Stockton Blvd, Sacramento, CA 95817 USA
[2] Univ Calif Davis, Sch Med, Dept Internal Med, Sacramento, CA 95817 USA
[3] Childrens Natl Hlth Syst, Div Emergency Med, Washington, DC USA
[4] Univ Utah, Sch Med, Dept Pediat, Salt Lake City, UT USA
[5] Baylor Coll Med, Dept Pediat, Houston, TX 77030 USA
[6] Baylor Coll Med, Ctr Clin Effectiveness, Houston, TX 77030 USA
[7] Boston Childrens Hosp, Div Emergency Med, Boston, MA USA
[8] Northwestern Univ, Dept Pediat, Feinberg Sch Med, Chicago, IL 60611 USA
[9] Univ Michigan, Dept Emergency Med & Pediat, Ann Arbor, MI 48109 USA
[10] Columbia Univ, Dept Pediat, Med Ctr, Columbia Univ Coll Phys & Surg, New York, NY 10027 USA
[11] Univ Calif Davis, Sch Med, Dept Emergency Med, Sacramento, CA 95817 USA
[12] Univ Penn, Childrens Hosp Philadelphia, Sch Med, Dept Pediat, Philadelphia, PA 19104 USA
[13] Michigan State Univ, Coll Human Med, DeVos Childrens Hosp, Dept Emergency Med, Grand Rapids, MI USA
[14] Hurley Med Ctr, Dept Emergency Med, Flint, MI USA
[15] Univ Michigan, Flint, MI 48503 USA
[16] Univ Colorado, Childrens Hosp Colorado, Div Emergency Med, Aurora, CO USA
[17] Univ Utah, Dept Pediat, Salt Lake City, UT USA
[18] PECARN Data Coordinating Ctr, Salt Lake City, UT USA
[19] Northwestern Univ, Feinberg Sch Med, Ann & Robert H Lurie Childrens Hosp, Dept Pediat, Evanston, IL 60208 USA