[1] Ohio State Univ, Coll Med, Dept Pediat, Columbus, OH 43210 USA
[2] Nationwide Childrens Hosp, Columbus, OH USA
[3] Nationwide Childrens Hosp, Ctr Perinatal Res, Res Inst, Columbus, OH USA
[4] Nationwide Childrens Hosp, Neonatal & Infant Feeding Disorders Res Program, Columbus, OH USA
[5] Ohio State Univ, Dept Econ, Columbus, OH 43210 USA
[6] Ohio State Univ, Ctr Human Resource Res, Columbus, OH 43210 USA