Design and Study Population
The study was carried out in a large inner-city tertiary care university teaching hospital in Virginia. Almost 2,000 babies are born each year in this hospital of which about 30% are Whites, 40% African Americans and 30% Hispanics or Latinos. A convenience sample of 803 mother-newborn dyad singletons were retrospectively recruited in the study using electronic health records (EHRs). The data included a sample of patients born from January 1, 2011 to December 31, 2019 divided almost equally yearly (i.e. almost 90 patients selected each year). The IRB of the Virginia Commonwealth University School of Medicine approved the study as expedited.