Purpose: Black/African American (AA) infants have been persistently observed with survival disadvantage compared to White infants in the USA, implying excess mortality. While reliable epidemiologic data continue to illustrate these disparities, data are yet to provide a substantial explanation to the observed rates and risk differences over the past six decades. We aimed in this study to examine the infant mortality risk differences by temporal trends and to provide an ecologic and non-concurrent explanation for the persisted variability.

Methods: A retrospective design with aggregate data from the Center for Disease Control and Prevention (CDC) was used to access the risk difference in cause-specific mortality, while stratification analysis was utilized for the risk ratio estimation. We also estimated the percent change for mortality trends.

Results: The cumulative infant mortality (IM) incidence was two times as likely for Black/AA relative to White, risk ratio (RR), 2.05. There were temporal trends in IM between 1968 and 2015 with excess IM among Black/AA children. Specifically, between 1968 and 2015, the percent change (% change) for digestive system disorders (58.43%); genito-urinary tract system disorders (58.20%); muscle, skeleton, and connective tissue disorders (66.60%); congenital anomalies (23.79%); and certain perinatal causes (38.65%) indicated upward trends in infant mortality Black/AA and White risk ratio. Except for neoplasm, and the initial study period (1968-1978) for congenital anomalies, Black/AA infants indicated survival disadvantage, implying excess mortality ratio relative to their White counterparts.

Conclusion: Disease-specific infant mortality is higher among black/AA except for neoplasm, and increasing percent changes are observed in digestive; genito-urinary; and muscle, skeleton, and connective tissue disorders. These findings are suggestive of the pressing needs to examine the cause of these disparities namely social determinants of health and social inequity for specific risk-adapted intervention in achieving health equity in US infant mortality.