[1] Nationwide Childrens Hosp, Ctr Surg Outcomes Res, Columbus, OH USA
[2] Ohio State Univ, Coll Med, Dept Surg, Nationwide Childrens Hosp,Div Pediat Surg, Columbus, OH 43210 USA
[3] Washington Univ, Sch Med, Dept Surg, Div Pediat Surg, St Louis, MO 63110 USA
[4] Northwestern Univ, Feinberg Sch Med, Div Pediat Surg, Dept Surg,Ann & Robert H Lurie Childrens Hosp Chi, Chicago, IL 60611 USA
[5] Med Coll Wisconsin, Dept Surg, Div Pediat Surg, 8700 W Wisconsin Ave, Milwaukee, WI 53226 USA
[6] Indiana Univ Sch Med, Div Pediat Surg, Dept Surg, Indianapolis, IN 46202 USA
[7] Univ Louisville, Sch Med, Dept Surg, Div Pediat Surg, Louisville, KY 40292 USA
[8] Childrens Mercy Hosp, Div Pediat Surg, Dept Surg, Kansas City, MO 64108 USA
[9] Univ Michigan, Dept Surg, Sect Pediat Surg, 1500 E Med Ctr Dr, Ann Arbor, MI 48109 USA
[10] Univ Wisconsin, Dept Surg, Sch Med & Publ Hlth, Div Pediat Surg, Madison, WI USA
[11] Univ Chicago Med & Biol Sci, Comer Childrens Hosp, Dept Surg, Sect Pediat Surg, Chicago, IL USA
[12] Cincinnati Childrens Hosp, Dept Pediat Surg, Cincinnati, OH USA