Evidence suggests that neighborhood deprivation may be associated with an increased risk of preterm birth (PTB, <37 weeks completed gestation). Black women, specifically, are more likely to have PTB and reside in deprived neighborhoods than their white counterparts. Few prior studies have examined this relationship in a cohort comprised solely of Black women and at multiple spatial levels. Our objective was to examine the association between area-level deprivation and the odds of PTB at the county, minor civil division (MCD), and census tract level in a Black cohort, and to determine if this association is modified by individual-level maternal characteristics. Women consented to participate in the BIBB study during a prenatal care visit and were surveyed to obtain addresses and individual-level data on age, income, and education among other covariates (n=1,239). Prenatal and hospital birth records of women who participated were abstracted to obtain multiple measures from which to categorize PTB. After exclusion for spontaneous abortion, therapeutic abortion, stillborn, or fetal death (n=17); women with missing gestational age data (n=47); missing residential address data (n-63); or lived in a Census tract that could not be linked to Census data (n=1); 1,112 women remained in the final sample size. Addresses from participants were geocoded and linked to data from the American Community Survey 5-year estimates. Six individual area-level characteristics were selected a priori for analyses: percent of population identifying as Black, unemployment rate, median household income, percent of population that is college educated, vacant housing rate, and percent on public assistance. An area-level deprivation index (ADI) was developed from a principal components analysis of the variables at the 3 aforementioned spatial levels. To examine the association between the ADI and the odds of PTB, odds ratios and 95% confidence intervals were estimated with sequentially-built generalized estimating equations (GEE). Models with the best fit were selected using the quasilikelihood information criterion (QIC). Effect modification by individual-level maternal characteristics, such as income and education, was also assessed using GEE. After controlling for maternal age, annual household income, and education level, no association was found between the ADI and the odds of PTB at the county and Census tract levels. At the MCD level, however, living in the most deprived neighborhood quartile, compared to living in the upper three quartiles, was found to be slightly protective of PTB (OR = 0.90, 95% CI: 0.84, 0.96). There was statistically significant effect modification of the association with PTB by maternal annual household income at all three spatial levels. Among women who resided in the highest quartile of area-level deprivation, women who were low income (< $30,000/year) were less likely to have PTB than their high-income (≥ $30,000/year) counterparts. We simultaneously examined effect modification by maternal annual household income and education level in a two two-way interaction model at the Census tract level. Among those with an annual household income of over $30,000 and who were not college educated, living in a high deprivation Census tract was associated with a 5-times increase in odds of PTB compared to those living in a low deprivation Census tract. Conversely, among those with a household annual household income of less than $30,000 and who were college educated, living in a high deprivation Census tract was associated with a 59% decrease in odds of PTB compared to those residing in a low deprivation Census tract. Area-level deprivation is a multidimensional construct that may influence a woman’s odds of PTB in several ways, and the impact it has on odds of PTB may vary across different spatial levels. Future research should further examine the association between area-level deprivation at multiple spatial levels and PTB risk, and further explore how this relationship may be moderated by various individual-level characteristics.
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