Economic status differences in infant mortality by cause of death.

Infant mortality differentials in a metropolitan aggregate of eight Ohio cities were examined for the years 1979-81. The primary analytical unit was the census tract of mother's usual residence. The independent variable was defined as the percentage of low-income families in each tract at the 1980 census. Results of the analysis revealed that in spite of some very substantial declines in the overall level of infant mortality in recent decades, there continues to be a pronounced inverse association between the aggregate economic status of an area and the probability that a newborn infant will not survive the first year of life. This inverse association characterizes both males and females, whites as well as nonwhites, and it is observed during both the neonatal and postneonatal age intervals. Moreover, it is apparent that the adverse influence of a low economic status is reflected in the incidence of mortality from all major exogenous and endogenous causes. Since these two cause groups have such different underlying determinants, this finding has important implications for the development and implementation of specific maternal and child health care policies and programs.