Neighborhood Privilege, Preterm Delivery, and Related Racial/Ethnic Disparities: An Intergenerational Application of the Index of Concentration at the Extremes.

We assessed whether early childhood and adulthood experiences of neighborhood privilege, measured by the Index of Concentration at the Extremes (ICE), were associated with preterm delivery and related racial/ethnic disparities using intergenerationally linked birth records of 379,794 California-born primiparous mothers (born 1982-1997) and their infants (born 1997-2011). ICE measures during early childhood and adulthood approximated racial/ethnic and economic dimensions of neighborhood privilege and disadvantage separately (ICE-income, ICE-race/ethnicity) and in combination (ICE-income + race/ethnicity). Results of our generalized estimating equation models with robust standard errors showed associations for ICE-income and ICE-income + race/ethnicity. For example, ICE-income + race/ethnicity was associated with preterm delivery in both early childhood (relative risk (RR) = 1.12, 95% confidence interval (CI): 1.08, 1.17) and adulthood (RR = 1.07, 95% CI: 1.03, 1.11). Non-Hispanic black and Hispanic women had higher risk of preterm delivery than white women (RR = 1.32, 95% CI: 1.28, 1.37; and RR = 1.11, 95% CI: 1.08, 1.14, respectively, adjusting for individual-level confounders). Adjustment for ICE-income + race/ethnicity at both time periods yielded the greatest declines in disparities (for non-Hispanic black women, RR = 1.23, 95% CI: 1.18, 1.28; for Hispanic women, RR = 1.05, 95% CI: 1.02, 1.09). Findings support independent effects of early childhood and adulthood neighborhood privilege on preterm delivery and related disparities.