The definition of sudden infant death syndrome (SIDS) originally appeared in 1969 and was modified 2 decades later. During the following 15 years, an enormous amount of additional information has emerged, justifying additional refinement of the definition of SIDS to incorporate epidemiologic features, risk factors, pathologic features, and ancillary test findings. An expert panel of pediatric and forensic pathologists and pediatricians considered these issues and developed a new general definition of SIDS for administrative and vital statistics purposes. The new definition was then stratified to facilitate research into sudden infant death. Another category, defined as unclassified sudden infant deaths, was introduced for cases that do not meet the criteria for a diagnosis of SIDS and for which alternative diagnoses of natural or unnatural conditions were equivocal. It is anticipated that these new definitions will be modified in the future to accommodate new understanding of SIDS and sudden infant death.

Objectives We have described national trends for the 5 leading external causes of injury mortality. Methods We used negative binomial regression and annual underlying cause-of-death data for US residents for 2000 through 2009. Results Mortality rates for unintentional poisoning, unintentional falls, and suicide increased by 128%, 71%, and 15%, respectively. The unintentional motor vehicle traffic crash mortality rate declined 25%. Suicide ranked first as a cause of injury mortality, followed by motor vehicle traffic crashes, poisoning, falls, and homicide. Females had a lower injury mortality rate than did males. The adjusted fall mortality rate displayed a positive age gradient. Blacks and Hispanics had lower adjusted motor vehicle traffic crash and suicide mortality rates and higher adjusted homicide rates than did Whites, and a lower unadjusted total injury mortality rate. Conclusions Mortality rates for suicide, poisoning, and falls rose substantially over the past decade. Suicide has surpassed motor vehicle traffic crashes as the leading cause of injury mortality. Comprehensive traffic safety measures have successfully reduced the national motor vehicle traffic crash mortality rate. Similar efforts will be required to diminish the burden of other injury.