Deaths attributable to injuries in infants, United States, 1983-1991

Objective To describe risk factors for injury death among infants in the Un ited States by the specific external cause of death. Methods. Data were analyzed from the US-linked birth/infant death files for the years 1983-1991. Potential risk factors for injury death were identifi ed from birth certificate data and included both maternal and infant factor s. Injury rates were calculated by external cause of death. Characteristics of infants who died from an injury were compared with those of the entire birth cohort. The independent effect of potential risk factors was assessed in multivariate analyses using a case-control study design. Results. A total of 10 370 injury deaths were identified over the 9-year st udy period (29.72/100 000 live births). The leading causes of death were ho micide, suffocation, motor vehicle crashes, and choking (inhalation of food or objects). There was no significant temporal trend in the overall rate o f injury death; however, this was because significant increases in the rate s of death from homicide (6.4%/year) and mechanical suffocation (3.7%/year) were offset by decreases in rates of death from fires (-4.7%/year) and cho king (-4.6%/year). In adjusted analyses, infants born to mothers with no pr enatal care, <12 years of education, two or more previous live births, Nati ve American race, or <20 years of age were at twice the risk of injury deat h compared with the lowest risk groups (initiation of prenatal care in the first trimester, greater than or equal to 16 years of education, no previou s live births, white, or greater than or equal to 25 years of age). When an alyzed by the specific cause of death, the factors that were associated mos t strongly with death varied. For example, Native Americans were at greates t risk of a motor vehicle related death (compared with whites: OR: 3.6; 95% CI: 1.8-7.1), and infants with birth weights of <1500 g were at greatest r isk of death attributable to inhalation of food (compared with greater than or equal to 2500 g: OR: 9.6; 95% CI: 3.3-28.0) or objects (OR: 11.8; 95% C I: 4.5-30.5). Conclusion. A number of sociodemographic characteristics are associated wit h an increased risk of injury-related death in infants. The strength of ass ociations between specific risk factors and death varies with the external cause of death, thus identifying high-risk subgroups for targeting of cause -specific interventions and simultaneously increasing our understanding of the individual and societal mechanisms underlying these tragedies.