United States black:white infant mortality disparities are not inevitable: identification of community resilience independent of socioeconomic status.

Abstract

U.S. disparities in Black:White infant mortality are persistent. National trends, however, may obscure local successes. Zero-corrected, negative binomial multivariable modeling was used to predict Black infant mortality (1999-2003) in all U.S. counties with reliable rates. Independent variables included county population size, racial composition, educational attainment, poverty, income and geographic origin. Resilient counties were defined as those whose Black infant mortality rate residual score was < 2.0. Mortality data was accessed from the Compressed Mortality File compiled by the National Center for Health Statistics and found on the CDC WONDER website. Demographic information was obtained from the US Census. The final model included the percentage of Blacks, age 18 to 64 years, speaking little or no English (P < .008), a socioeconomic index comprising educational attainment, poverty, and per capita income (P < .001), and household income in 1990 (P < .001). After accounting for these factors, a stratum comprising Essex and Plymouth Counties, Mass.; Bronx, N.Y.; and Multnomah, Ore. was identified as unusually resilient. Percentage of Black poverty and educational attainment in Black women in the resilient stratum approximated the average for all 330 counties. In 1979, Black infant mortality in the resilient stratum (23.6 per 1000 live births) exceeded Black US infant mortality (22.6). By 2001, Black infant mortality in the resilient stratum (5.6) was below the corresponding value for Whites (5.7). Resilient county neonatal mortality declined both early and late in the observation period, while post-neonatal declines were most marked after 1996. Models for reduction/elimination of racial disparities in US infant mortality, independent from county-level contextual measures of socioeconomic status, may already exist.