Table 1.

Baseline Subject Characteristics

N(%)MeanSD
Biomedical
 Birth weight 420–1500 g2031174.1227.4
 Gestational age 25–37 weeks20330.92.1
 Neonatal Health Index (NHI)*
 −42.3–+147.3
19887.221.5
 Small for gestational age (SGA)203(38%)
Sociodemographic
 Maternal education203
  None beyond elementary school(4%)
  Some high school(37%)
  High school graduate(33%)
  Some college(21%)
  College degree or higher(5%)
 Racial and ethnic background197
  White(9%)
  African-American(51%)
  Latino(38%)
  Other(2%)
  • * NHI = days in hospital adjusted for birth weight, standardized to a mean of 100.