Infant and Youth Mortality Trends by Race/Ethnicity and Cause of Death in the United States.

Importance: The United States has higher infant and youth mortality rates than other high-income countries, with striking disparities by racial/ethnic group. Understanding changing trends by age and race/ethnicity for leading causes of death is imperative for focused intervention. Objective: To estimate trends in US infant and youth mortality rates from 1999 to 2015 by age group and race/ethnicity, identify leading causes of death, and compare mortality rates with Canada and England/Wales. Design, Setting, and Participants: This descriptive study analyzed death certificate data from the US National Center for Health Statistics, Statistics Canada, and the UK Office of National Statistics for all deaths among individuals younger than 25 years. The study took place from January 1, 1999, to December 31, 2015, and analyses started in September 2017. Exposures: Race/ethnicity. Main Outcomes and Measures: Average annual percent changes in mortality rates from 1999 to 2015 and absolute rate change between 1999 to 2002 and 2012 to 2015 for each age group, race/ethnicity, and cause of death. Results: Among individuals from birth to age 24 years, 1 169 537 deaths occurred in the United States, 80 540 in Canada, and 121 183 in England/Wales from 1999 to 2015. In the United States, 64% of deaths occurred in male individuals and 52.6% occurred in white individuals (25.1% deaths occurred in black individuals and 17.9% in Latino individuals). All-cause mortality declined for all age groups (infants younger than 1 year [38.5% of deaths], children aged 1-9 years [10.6%], early adolescents aged 10-14 years [5%], late adolescents aged 15-19 years [17.7%], and young adults aged 20-24 years [28.1%]) in the United States, Canada, and England/Wales from 1999 to 2015. However, rates were highest in the United States. Within the United States, annual declines in all-cause mortality rates occurred among all age groups of black, Latino, and white individuals, except for white individuals aged 20 to 24 years, whose rates remained stable. Mortality rates declined across most major causes of death from 1999 to 2002 and 2012 to 2015, with notable declines observed for sudden infant death syndrome, unintentional injury death, and homicides. Among infants, unintentional suffocation and strangulation in bed increased (difference between 2012-2015 and 1999-2002 range, 6.11-29.03 per 100 000). Further, suicide rates among Latino and white individuals aged 10 to 24 years (range, 0.21-2.63 per 100 000) and black individuals aged 10 to 19 years (range, 0.10-0.45 per 100 000) increased, as did unintentional injury deaths in white young adults (0.79 per 100 000). The rise in unintentional injury deaths is attributed to increases in drug poisonings and was also observed in black and Latino young adults. Conclusions and Relevance: Mortality rates in the United States have generally declined for infants and youths from 1999 to 2015 owing to reductions in sudden infant death syndrome, unintentional injury death, and homicides. However, US mortality rates remain higher than Canada and England/Wales, with particularly elevated rates among black and American Indian/Alaskan Native youth. Further, there is a concerning increase in suicide and drug poisoning death rates among US adolescents and young adults.