[1] Childrens Mercy Kansas City, Div Neonatol, Kansas City, MO 64108 USA
[2] Levine Childrens Hosp Atrium Hlth, Div Neonatol, Charlotte, NC USA
[3] Univ Missouri, Hlth Serv & Outcomes Res, Childrens Mercy Kansas City, Kansas City, MO 64110 USA
[4] Univ Missouri, Sch Med, Kansas City, MO 64110 USA
[5] Univ Missouri, Biostat & Epidemiol Core, Hlth Serv & Outcomes Res, Childrens Mercy Kansas City, Kansas City, MO 64110 USA