Associations between area-level deprivation at the Census tract level and preterm birth in the Biosocial Impact of Black Births (BIBB) Study

U.S.-born Black women are more likely to have a preterm birth (PTB) and reside in deprived neighborhoods than their white counterparts. Our objectives were to examine the effect of area-level deprivation on the risk of PTB and to determine if this association was modified by mother's educational level and/or annual household income. Our population consisted of 1,239 Black women in the Biosocial Impact on Black Births (BIBB) study, a prospective cohort study of pregnant Black women in Detroit, Columbus, and Orlando. To quantify deprivation, an area-level deprivation index (ADI) was developed from a principal components analysis of area-level characteristics at the Census tract level. To examine the association between ADI and PTB, the multi-level generalized linear models were estimated using the generalized estimating equations method, controlling for mother's age, education and income. The best fit model included two 2-way interactions for the individual-level factors of maternal education and annual household income. Findings show that among women with no college education making at least $30,000/year, those who resided in high deprivation neighborhoods had over 3 times greater risk of delivering preterm than their counterparts in low deprivation neighborhoods. Education and income were both important moderators and operated in the opposite direction on risk of PTB: Having some college education was protective association on PTB in women living in high deprivation tracts, while having a higher income (at least $30,000/year) was harmful. Future research should seek to confirm the increased vulnerability to PTB for Black women with higher household incomes who also live in highly deprived Census tracts in U.S. metropolitan areas.