PLoS ONE (Jan 2014)

Population-level correlates of preterm delivery among black and white women in the U.S.

  • Suzan L Carmichael,
  • Mark R Cullen,
  • Jonathan A Mayo,
  • Jeffrey B Gould,
  • Pooja Loftus,
  • David K Stevenson,
  • Paul H Wise,
  • Gary M Shaw

DOI
https://doi.org/10.1371/journal.pone.0094153
Journal volume & issue
Vol. 9, no. 4
p. e94153

Abstract

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ObjectiveThis study examined the ability of social, demographic, environmental and health-related factors to explain geographic variability in preterm delivery among black and white women in the US and whether these factors explain black-white disparities in preterm delivery.MethodsWe examined county-level prevalence of preterm delivery (20-31 or 32-36 weeks gestation) among singletons born 1998-2002. We conducted multivariable linear regression analysis to estimate the association of selected variables with preterm delivery separately for each preterm/race-ethnicity group.ResultsThe prevalence of preterm delivery varied two- to three-fold across U.S. counties, and the distributions were strikingly distinct for blacks and whites. Among births to blacks, regression models explained 46% of the variability in county-level risk of delivery at 20-31 weeks and 55% for delivery at 32-36 weeks (based on R-squared values). Respective percentages for whites were 67% and 71%. Models included socio-environmental/demographic and health-related variables and explained similar amounts of variability overall.ConclusionsMuch of the geographic variability in preterm delivery in the US can be explained by socioeconomic, demographic and health-related characteristics of the population, but less so for blacks than whites.