Birthweight-specific infant mortality risks for Native Americans and whites, United States, 1960 and 1984

We used NCHS natality and linked-birth/death certificate tapes to compare birthweight-specific neonatal and postneonatal mortality risks for Native Americans and whites in 1960 and in 1984. The birthweight distributions for the two groups were similar both years. Native American neonatal mortality risk dropped from 20.2 in 1960 to 5.2 in 1984, and the relative risk for Native Americans with respect to whites fell from 1.31 in 1960 to a nonsignificant difference in 1984. Postneonatal mortality risks for Native Americans fell from 27.5 in 1960 to 6.2 in 1984, with a drop in the relative risk from 5.2 to 2.1. Although the relative improvements for Native Americans were highest in postneonatal survival, Native Americans still had over twice the level of white postneonatal mortality. Birthweight was positively associated with survival for both groups, but the odds of Native American neonatal death were affected less by low and very low birthweights. For both groups, improvements in neonatal mortality were highest at the lower birthweights, while the gains in postneonatal survival benefitted normal and high birthweight infants most.