Due to socioeconomic development, mortality rates from infectious diseases have declined significantly (1). However, injuries are becoming an increasingly main threat to the health of children, because they are common causes of disability, and involve high healthcare costs (2). The Global Burden of Disease Study reported that over 3 million people died from unintentional injuries in 2015, of whom children aged <15 years comprised nearly 20% of the deaths (3). Furthermore, findings presented by the Chinese Children’s Safety Network showed that 200,000 children die from injuries each year (mortality rate, 67.13/100,000), which is 1.5 times that of South Korea and 2.5 times that of the United States, and it is increasing at an annual rate of 7%−10% (4). Tens of millions of children seek medical treatment for injuries, and some are left with lifelong disabilities that place a heavy burden on society, families, and individuals. Therefore, it is imperative to prevent and manage injuries to protect children’s health.

China is a vast country with complex geographical conditions, with each region having different manifestations of child injuries according to their living habits and environment (5, 6). Child injuries are also closely related to economic developmental levels associated changes, and resulting protective measures adopted (7–9).

The Southwest Medical University is located in the south of Sichuan, China, which bordering Yunnan, Guizhou, Sichuan, and Chongqing provinces, has diverse topography, numerous ethnic groups, different living habits, and varying economic developmental levels. While the characteristics of child injuries in this region compared with other regions of China might differ, and evolve with socioeconomic development, no relevant study to date has reported on child injuries within this region. Meanwhile, our hospital is the region’s most important medical centre; thus, its inpatient data is partially representative of the population to some extent. This study aimed to retrospectively investigate the clinical characteristics and changes over time in child injuries, evaluate the possible risk factors for different injury outcomes, and determine relevant injury-related health resource costs, to provide evidence-based guidance on future prevention and treatment of child injuries within southern Sichuan region, where our hospital is located.

We retrospectively investigated clinical data concerning children aged between 29 days and 18 years and hospitalised for injuries at the affiliated hospital of Southwest Medical University from January 1, 2017 to December 31, 2021. If a paediatric patient was admitted multiple times for sequelae owing to an injury, only the first injury-related case was recorded. If a paediatric patient had a combination of multiple types of injuries, the most predominant type of injury was recorded. Paediatric patients with a hospital stay <24 h, missing hospitalisation data, and an unknown prognosis were excluded. Diagnosis codes were entered according to the WHO International Classification of Diseases (ICD-10) and included the following 14 types of injury: road traffic injuries, falls, burns, sharps injuries, bruises, smash injuries, crush injuries, blast injuries, bites, electrocution, drowning, poisoning, foreign body injuries, and others/unknown. Age was divided into five groups according to Paediatrics (9th Edition) as follows: infancy (28 days-<1 year), early childhood (1-<3 years), preschool (3-<6 years), school age (6-<10 year), and adolescence (10-<18 years). Places of residence are divided by the state administrative departments into villages, towns, counties, and urban areas.

We analysed data concerning the basic characteristics of the paediatric patients (sex, age, place of residence, location of injury, and season), evolution of injury characteristics over time, risk factors for events with adverse outcomes (defined as one or more organ dysfunction or death occurs), and medical resource costs.

SPSS version 26.0 (IBM Corp., Armonk, NY, USA) was used for statistical analyses. Count data are expressed as a proportion (%). Furthermore, measurement data conforming to a normal distribution are expressed as mean ± standard deviation (X̄ ± S), whereas measurement data with skewed distribution are expressed as median (M, interquartile range, P₂₅–P₇₅). A chi-square test was used to explore the significance of differences between groups, and Fisher’s exact test was used when the conditions for a chi-square test were not met. Additionally, a t-test was used for normally distributed data, and a Kruskal-Wallis rank sum test was used for not normally distributed data. A Spearman’s rank correlation coefficient was used to analyse the correlation between different indicators, and a multinomial logistic regression model was used to evaluate potential risk factors. Statistical significance was set at a P-value < 0.05.

In this study, we found that childhood injuries occurred predominantly in boys, in rural areas, at home, during spring and summer with a peak in July. These findings are consistent with those reported in previous studies in other regions of China (10, 11). One explanation may be that men tend to be more physically active and thus may be more prone to injuries. The other explanation could be that, our hospital is located in the southernmost region of China, has a notably warmer weather in spring and summer, with the summer vacation being in July. These environmental factors might contribute to a higher occurrence of unintentional injuries in July. However, the most common types of injuries in our region were falls, burns, road traffic injuries, poisoning, and foreign object injuries. These findings are not entirely consistent with that of domestic and foreign regions (12–14), which showed that burns and poisonings being less frequent. This variation may be due to our region have many mountainous areas, cold winters, and residents relying on burning charcoal for heat. In addition, the village areas are extensive and mainly agriculture-oriented; thus, the use of pesticides and herbicides is higher than that in industrial areas, which may explain the higher number of children being poisoned. Our findings also showed that more adolescent patients were hospitalised for injuries. Our review of the previous literature found that the age group with the highest prevalence of injuries predominately involved older children (15, 16). Contrary to popular belief, adolescents tend to be more vulnerable to injuries than younger children. This is because guardians may assume that adolescents have a better sense of safety than younger children, and neglect supervising them; However, their awareness of safety is actually immature. Therefore, attention should be paid to this population in relation to injury prevention.

In terms of the changes along the timeline, we found that our hospital had an average of 27.50 per 100,000 paediatric patients hospitalised for injuries every year, male children consistently predominated, and the proportion of injuries occurring in village areas consistently remained high. This suggests that the risk of child injuries is significant and that their prevention and management should be strengthened, particularly in male children in village areas. Interestingly, the number of injured patients was a slight decreasing in 2019–2020, which we presumed to be a direct consequence of the strict preventative measures taken during the COVID-19 pandemic. During that period, children stayed at home with their guardians for a longer time, had a significant reduction in social activities, and may have been better cared for; thus, fewer injuries occurred. This also proves that the injuries are preventable as long as the three factors of injury prevention are well taken into account, the factors affecting injury proposed by John Gordon (17): host, pathogenic, and environmental.

In this study, the proportion of intentional injuries was significantly higher after 2019. Further analysis indicated that those with intentional injuries predominantly comprised adolescent girls in village areas, most took poisons or medications to intentionally harm themselves. This result is consistent with findings reported by Zhu et al. (18). Intentionally injured older children may often have depression or be in intense emotional conflict with their guardians, peers, or teachers (18). Data show that the rate of poisoning in children due to exposure to antidepressants has increased to 1,793 cases per year (5.8%/year) over the past ten years, leading to events with extremely serious adverse prognoses (19). Depression and anxiety, which are mood disorders, were once considered ‘urban diseases’, more likely to occur in economically developed areas. However, owing to recent rapid economic development in China, regions which had previously been economically underdeveloped are now presenting with increasing numbers of individuals with depression and anxiety, suggesting that extra attention should be paid to in future.

This study also showed that road traffic injuries was consistently the third most common type and a most likely risk factor to cause adverse outcomes, consistent with studies in other regions in China (20), Australia (21) and Canada (22). This could be linked to increasing vehicle ownership rates have resulted in a higher incidence rate of road traffic injuries (23), which is more likely to lead to multiple organ function impairment. China’s legislation on the protection of minors stipulates that vehicles should be equipped with child safety seats (CSSs) (24). However, most parents consider CSSs optional and prefer to hold their children on their laps, considering this to be safer (25), particularly in western areas of China. So, stricter implementation of this law concerning the use of CSSs is needed. Furthermore, the falls were consistently the most common cause of injury and the second most likely factor leading to a poor prognosis. Adolescents from villages had a higher number of poor prognostic outcomes, consistent with previous research results (26, 27). Indicating that road traffic injuries, falls, and adolescents from villages should be targeted in terms of injury prevention in the future.

The average annual hospitalisation costs of child injuries in our hospital were $2312.22. Of all injuries, road traffic injuries and falls were the most costly injuries, in line with Australia (21) and India (28). Compared with other diseases, the costs of child injuries are higher than that of asthma ($1723), acute upper respiratory infections ($2057) and influenza ($2072), comparable to bronchiolitis ($2602) and pneumonia ($2929) (29). And it’s significantly higher than that in Northwest China 10 years ago ($166) (30), indicating that the costs of child injuries are constantly increasing. In order to reduce the financial burden, more measures should be taken to prevent children from injury in the future.

Child injuries continue to be a serious issue, with males and adolescents from villages predominantly affected. Further attention should also be paid to intentional injuries among female adolescents. Road traffic injuries and falls were the most harmful types of injuries in terms of occurrence proportion, clinical outcomes, and medical resource costs; thus, prevention and management strategies should be strengthened.