Socioeconomic position, health behaviors, and racial disparities in cause-specific infant mortality in Michigan, USA

- Socioeconomic position (SEP) and maternal risk behaviors differ by race.
- We explored how these factors explain disparities in infant mortality (IM) by cause.
- They explained nearly a third of the disparity in IM overall.
- They explained over 30% of disparities in key causes, like sudden infant death.
- They explained less of disparities in other causes, like congenital anomalies.

ObjectivesStudies about racial disparities in infant mortality suggest that racial differences in socioeconomic position (SEP) and maternal risk behaviors explain some, but not all, excess infant mortality among Blacks relative to non-Hispanic Whites. We examined the contribution of these to disparities in specific causes of infant mortality.MethodsWe analyzed data about 2,087,191 mother-child dyads in Michigan between 1989 and 2005. First, we calculated crude Black-White infant mortality ratios independently and by specific cause of death. Second, we fit multivariable Poisson regression models of infant mortality, overall and by cause, adjusting for SEP and maternal risk behaviors. Third, Crude Black-White mortality ratios were compared to adjusted predicted probability ratios, overall and by specific cause.ResultsSEP and maternal risk behaviors explained nearly a third of the disparity in infant mortality overall, and over 25% of disparities in several specific causes including homicide, accident, sudden infant death syndrome, and respiratory distress syndrome. However, SEP and maternal risk behaviors had little influence on disparities in other specific causes, such as septicemia and congenital anomalies.ConclusionsThese findings help focus policy attention toward disparities in those specific causes of infant mortality most amenable to social and behavioral intervention, as well as research attention to disparities in specific causes unexplained by SEP and behavioral differences.