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

Objective To describe risk factors for injury death among infants in the United 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 identified from birth certificate data and included both maternal and infant factors. 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 study period (29.72/100 000 live births). The leading causes of death were homicide, suffocation, motor vehicle crashes, and choking (inhalation of food or objects). There was no significant temporal trend in the overall rate of injury death; however, this was because significant increases in the rates 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 choking (-4.6%/year). In adjusted analyses, infants born to mothers with no prenatal care, <12 years of education, two or more previous live births, Native American race, or <20 years of age were at twice the risk of injury death compared with the lowest risk groups (initiation of prenatal care in the first trimester, greater than or equal to 16 years of education, no previous live births, white, or greater than or equal to 25 years of age). When analyzed by the specific cause of death, the factors that were associated most strongly with death varied. For example, Native Americans were at greatest 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 risk 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% CI: 4.5-30.5). Conclusion. A number of sociodemographic characteristics are associated with an increased risk of injury-related death in infants. The strength of associations 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.