Neighborhood deprivation and preterm birth: an application of propensity score matching

PurposeOn the basis of a neighborhood deprivation index (NDI), this study aims to examine the association between neighborhood deprivation and preterm birth (PTB) by applying propensity score matching (PSM) methods.MethodsNDI was calculated for all census tracts in South Carolina based on the US Census data. Live births in South Carolina during 2008 to 2009 (n = 98,456) were assigned to an NDI quartile group based on residential addresses. PSM was used to create matched pairs by NDI quartiles to avoid any potential inference on imbalanced data. The differences of prevalence of PTB were calculated for exposed and reference deprivation groups.ResultsNeighborhood deprivation was higher among blacks than whites. The overall prevalence of PTB was 8.5% for whites and 12.6% for blacks. Living in neighborhoods with higher deprivation was associated with increased risk of PTB among blacks compared with living in neighborhoods with lower deprivation among blacks. However, random-effect regression models showed that the most deprived whites experienced 1.13 times the odds of having PTB than the least deprived whites.ConclusionsThe racial disparities in adverse birth outcomes might be partially explained by neighborhood deprivation in South Carolina. PSM may be an appropriate approach to avoid imbalanced data inferences.