Injury Mortality of Children and Adolescents Aged 0–19 Years — China, 2010–2021

Introduction To examine the recent trends in child injury mortality in China. Methods Injury mortality data of 2010–2021 for children and adolescents aged 0–19 years were from the China Health Statistics Yearbook. Injury mortality disparities across urban vs. rural locations, gender, and age groups were scrutinized. Annual percent change (APC), average annual percent change (AAPC), and their 95% confidence intervals (95% CI) were estiamted usimg Joinpoint regression models. Results The age-standardized injury mortality significantly dropped from 21.87 to 9.41 per 100,000 population among children and youth aged 0–19 years during 2010–2021, with an AAPC of −6.7% (95% CI: −8.2%, −5.2%). The urban-rural disparity and gender gap in injury mortality reduced gradually. In 2021, drowning and road traffic crashes were the top two causes of child injury deaths, explaing 31.1% and 27.9% of total injury deaths, respectively. Suffocation accounted for 62.3% of injury deaths among infants younger than a year. Alarmingly, the suicide mortality rate rose from 2.16 to 3.42 per 100,000 population between 2010 and 2021 among teenagers aged 15–19 years. Subgroup analyses yielded similar results. Conclusions During 2010–2021, the injury mortality decreased significantly among Chinese children and adolescents, and the responding urban-rural disparities narrowed.

Statistical Yearbook (2010-2021), which provides agespecific mortality data for 11 categories of unintentional and intentional injuries (8): motor vehicle crashes, non-motor vehicle crashes, poisoning, falls, fire/burn injuries, drowning, mechanical suffocation, falling object injuries, electric shocks, homicide, and suicide.To estimate the year-end population for each year from 2010 to 2021, we employed linear interpolation (9) using China's census data of 2010 and 2020.The population data from 2020 was then utilized as the standard population for calculating age-standardized injury mortality.
Linear graphs were utilized to display variations in both overall and subgroup injury mortality, separated by area, gender, and age group for Chinese children and adolescents aged 0 to 19 years.Furthermore, stacked area charts were constructed to show the cause spectrum of child and adolescent injury mortality from 2010 to 2021, segmented by area and age group.
Significant injury mortality changes throughout the study time period were quantified using average annual percent change (AAPC) and annual percent change (APC), alongside their corresponding 95% confidence intervals (95% CIs), which were estimated via Joinpoint regression models.We used the Joinpoint Regression Program (Version 4.9.1.0,National Cancer Institute, Calverton, USA) to perform statistical analysis.

Subgroup Injury Mortality by Age Group, Sex, and Area
Between 2010 and 2021, age-standardized injury mortality decreased from 28.52 to 11.24 per 100,000 population for boys, and decreased from 14.34 to 7.30 per 100,000 population for girls.The age-standardized injury mortality for boys was continuously higher than and declined faster than that for girls in both urban and rural areas (Figure 2A and Table 2).

Cause Spectrum of Injury Mortality by Age Group and Area
Supplementary Figure S1 (available at https:// weekly.chinacdc.cn/)depicts the distribution of the top six causes of injury-related deaths, segmented by age group and geographical area.Drowning and road traffic crashes were the predominant causes of injuryrelated mortality for the four older age groups.Among infants under the age of 1 year, suffocation emerged as the primary cause, accounting for 56.0%-76.7% of injury deaths during 2010-2021.Suicide has come to light as a significant cause of injury-related deaths among adolescents aged 10-19 years.
In contrast, notable suicide mortality increases were observed in the two oldest age groups for both urban and rural areas (with an AAPC changing between 4.7% and 11.5%) (Supplementary Figure S1 and Supplementary Table S4, available at https://weekly.chinacdc.cn/).

DISCUSSION
This study, using nationally representative data, analyzed current trends in injury mortality among Chinese children aged 0-19 years.The research produced four critical findings: First, the overall agestandardized injury mortality saw a decrease of 57% between 2010 and 2021.Second, the mortality rate due to injuries was comparatively higher in rural areas and among boys, with a faster decline rate than in urban areas and among girls.Third, the predominant cause of injury mortality differed by age groups, where unintentional suffocation was the leading cause of death for infants under one year and drowning was the main cause for the four older age groups.Lastly, suicide emerged as a leading cause of injury mortality among adolescents aged 10-19 years.
The significant decrease in injury mortality rates in Chinese children and adolescents over the past ten years are likely be attributed to two main factors.First, the reduction may symbolize the enormous efforts made by the Chinese government regarding injury prevention.As an instance, the implementation of changes to traffic laws -such as making drunk driving a criminal offense -has decreased traffic crash risks (10).Furthermore, the Chinese administration issued a variety of injury prevention guidelines and commenced education programs in schools across the country.These initiatives probably have a positive impact on child injury prevention.
Second, the notable decline in mortality due to injuries might be correlated with the swift urbanization throughout the nation.The percentage of Chinese residents residing in rural areas dropped from 48.17% in 2011 to 35.28% in 2021 (11).This could possibly lead to lower exposure to specific injury risks and hazards, such as drowning, for children.
Our results corroborate earlier findings that injuryrelated death rates are significantly elevated among children in rural regions and boys, compared to their urban and fema counterparts (5).The heightened injury mortality rates among young people in China's rural areas are linked to insufficient adult supervision of children who are left behind (12), as well as a lack of adequate public facilities including readily accessible medical centers.The higher injury fatality rates among boys could be attributed to their increased physical activity, impulsivity, and heightened energy levels, predisposing them to engage in high-risk behaviors (5).
The substantial decrease in injury mortality rates in rural areas between 2010 and 2021 is promising.It may be attributable to accelerated socio-economic advancement experienced in rural China over the past decade.The National Precision Poverty Alleviation Project has seen considerable progress in strengthening rural economic growth and distribution of healthcare resources.From 2010 to 2021, there was an impressive 115.8% rise in the number of health technicians per thousand population in rural sectors, greatly surpassing the 32.9% increase observed in urban sectors (8).Furthermore, the count of children left behind in rural primary and middle schools declined from 15.51 million in 2017 to 12.00 million in 2021 (11).
Our findings indicate that the reasons for injuryrelated mortalities vary among the five age groups, reflecting different levels of exposure to certain hazards during various stages of child development.Infants under one-year-old, for instance, are more prone to unintentional suffocation due to underdeveloped respiratory systems, making them susceptible to potentially fatal obstructions while eating, playing, or sleeping (13).Older children, on the other hand, are more likely to engage in dangerous activities when left unsupervised, especially near roads or bodies of water (1).During adolescence, the rapid maturation of the brain and hormonal changes coupled with increased exposure to internet and social media, may exacerbate interpersonal stress and emotional instability (14).Such factors could potentially contribute to a rise in suicide rates among adolescents (14).The escalating trend of adolescent suicides that we have observed in China mirrors a global pattern, although the reported rates in China remain lower than in many other countries (15).Our findings have two policy implications.First, the substantial injury mortality reductions suggest that government goals to reduce child and adolescent injury mortality between 2011 and 2020 have been successful in China.Reduced injury mortality gaps between urban and rural areas and between boys and girls indicate slight improvement in reducing disparities and achieving injury mortality equity across population subgroups.
Second, systematic and intensified prevention efforts should continue according to prevention priorities listed by the Child Development Program of China (2021-2030).Priority should be identification of a government department responsible for injury prevention programs in China to lead implementation of proven prevention programs nationwide like the recent adoption of national child safety seat law.
This study has several limitations.First, due to the absence of data on non-fatal injuries, the results for injury morbidity over the past decade may differ.Second, because data were lacking, this research did not study relevant influencing factors.Conducting research to identify associated risk factors is necessary to fully interpret epidemiological data trends, quantify causal relations between influencing factors and injury mortality, and develop prevention programs.

CONCLUSIONS
From 2010 to 2021, there was a significant decline in child injury mortality in China.Moreover, injury mortality disparities across area (urban vs. rural) and gender (boys vs. girls) diminished during this period.

FIGURE 1 .
FIGURE 1. Age-standardized and age-specific mortality rates for injuries among children and adolescents in various regions of China, from 2010 to 2021.(A) Age-standardized injury mortality rates in individuals aged 0-19 segmented by area.(B) Mortality caused by injuries in children under 1 year, differentiated by area.(C) Injury-caused mortality in children aged 1-4, broken down by area.(D) Injury-associated mortality in children aged 5-9, classified by area.(E) Mortality due to injuries in adolescents aged 10-14, outlined by area.(F) Injury mortality trends in adolescents aged 15-19, divided by area.

FIGURE 2 .
FIGURE 2. Overall age-standardized and age-specific mortality rates due to injury among Chinese children and adolescents, categorized by sex and area, spanning the years 2010-2021.(A) Age-standardized injury mortality in children and adolescents aged 0-19, separated by sex and area.(B) Injury mortality in infants under one year of age, reported by sex and area.(C) Injury mortality in toddlers aged 1-4, delineated by sex and area.(D) Injury mortality in young children aged 5-9, categorized by sex and area.(E) Injury mortality in early adolescents aged 10-14, divided by sex and area.(F) Injury mortality in late adolescents aged 15-19, sorted by sex and area.
. Distribution of injury-related mortality by area and age group in Chinese children and adolescents, from 2010 to 2021.(A) Injury-related mortality distribution in children and adolescents aged 0-19 in urban areas.(B) Injury-related mortality distribution in children and adolescents aged 0-19 in rural areas.(C) Injury-related mortality distribution in children under 1 year in urban areas.(D) Injury-related mortality distribution in children under 1 year in rural areas.(E) Injury-related mortality distribution in children aged 1-4 in urban areas.(F) Injury-related mortality distribution in children aged 1-4 in rural areas.(G) Injury-related mortality distribution in children aged 5-9 in urban areas.(H) Injury-related mortality distribution in children aged 5-9 in rural areas.(I) Injury-related mortality distribution in adolescents aged 10-14 in urban areas.(J) Injury-related mortality distribution in adolescents aged 10-14 in rural areas.(K) Injury-related mortality distribution in adolescents aged 15-19 in urban areas.(L) Injury-related mortality distribution in adolescents aged 15-19 in rural areas.China CDC Weekly S6 CCDC Weekly / Vol.6 / No. 14 Chinese Center for Disease Control and Prevention

TABLE 1 .
APC and AAPC in injury mortality among Chinese children and adolescents from 2010 to 2021.

TABLE 2 .
Mortality due to injuries and AAPC among Chinese children and adolescents, categorized by sex, from 2010-2021.

TABLE S1 .
The dramatic injury mortality decrease likely echoes the impact of governmental interventions.Considering the notably high child injury mortality, however, comprehensive and intensified efforts are encouraged to meet the objectives set forth by the Child Development Program of China (2021-2030).APC and AAPC in injury-related mortality among Chinese boys from 2010 to 2021.
SUPPLEMENTARY TABLES3.AAPC in mortality rates due to injuries among Chinese children and adolescents, segregated by age group and region, from 2010 to 2021.