Infant death rates among the poor and nonpoor in Kentucky, 1982 to 1983.

The mortality rates of infants born in Kentucky during 1982 and 1983 were analyzed to determine whether there were differences between poor and nonpoor infants. We used computer matching with the Social Insurance Food Stamp files and with the Aid for Families With Dependent Children files to define poor and nonpoor Kentucky resident families. The crude death rate for poor infants was 13.7/1,000 births, and the nonpoor death rate was 10.8/1,000 births. After adjusting for several important variables, we found that the poor infant was at a significantly greater risk for death than the nonpoor infant but only during the postneonatal period (relative risk 2.04, P = .0003). Some differences by sex and race were noted. Sudden infant death syndrome and infections were largely responsible for the poor infants' higher postneonatal mortality risk.