Childhood injury is a major public health problem around the world [1]. Over 90 % of injuries to children occur in low- and middle-income countries [2]. In Chinese society, unintentional injuries are the most common cause of morbidity and mortality for children under age 14, and those injuries have negative impacts not only on children but also on their families [3].

An unintentional injury is a fatal or non-fatal physical injury that occurs suddenly [4]. The prevalence rate of unintentional injury in China ranges from 11.3 to 13.9 % among children who had medically attended injuries before age 14 [3, 5, 6]. Falls, burns, and motor vehicle crash are the most common types of childhood injury [7]. The mortality rate for unintentionally injured children under 14 is about 0.7 % and accounts for 31.3 % of total child deaths in China [8]. In Beijing China, more than 10 % of children under age 14 required medical care for injuries in 2003, and the annual medical cost was at least ¥82 million (about US $14 million) [9]. The burdens of pediatric injury may overload the families of the injured children and may put an indirect burden on society as well. There are no national cost statistics available for China as a whole; however, in Guangdong Province, medical costs for disability care and non-routine medical treatment for elementary and middle school students between 1998 and 1999 have been estimated at about ¥369 million (about $62 million) [10].

Previous studies have identified that unintentional injuries in children are associated with socioeconomic and environmental factors, including poverty, low education level of parents, young age of mother, unemployed/underemployed father, poor parental supervision, and unsafe utilities at home or playground [11–13]. The characteristics of the affected children are also associated with the prevalence of unintentional injuries. For example, boys who have experienced injury tend to have a difficult type of temperament, a lower ability to concentrate on homework, greater academic stress, and various behavior disorders [14–16].

Although children may be injured in a variety of different places, studies reveal that unintentional injury tends to occur more often at home for toddlers and preschoolers, while elementary school children are more likely to be injured outdoors [17, 18]. The explanation for this may be related to exposure (in the home vs. outdoors) [19]. Some studies that have focused on the association between behavior disorders (e.g., hyperactivity, aggression, anxiety) and injury, most have focused on preschoolers; few studies have paid attention to these factors in school-age children [20]. Therefore, the aim of this study was to compare differences in behavioral characteristics between Chinese 6 to11 year old/1^st to 5^th grade school-age children who sustained a non-fatal unintentional injury in the previous year and children who did not sustain an injury. That data were further used to identify risk behavior factors for the injured children.

Results from this study showed that the incidence of unintentional injury for the group as a whole was 17.9 %, which is higher than the earlier reports for children aged 14 and under in China [3, 5]. Previous studies showed that boys experience injury more frequently than girls in all age groups [26, 27]; however, there was no statistically significant difference between boys (9.5 %) and girls (6.5 %) in this study (p = 0.815), though the boys did have a higher incidence of injury than girls. In the present study, injury often happened either at home or at school, which differed from the findings of previous studies where injuries often occurred in a public place [17, 18, 28]. One reason for the difference may lie in differences in the nature of the children’s activity. In this study, boys spent more time using the computer at home, thus decreasing the outdoor risk exposure [29]. Also, in this study, parents in the boys’ injury group had a statistically significant higher education level compared to the control group parents, which was inconsistent with other researchers’ findings [11–13]. The higher incidence of injury might be due to higher-educated parents having less time with their children because of work commitments that kept them away from home. These working parents may have been compelled to leave their children in higher risk environments for longer periods than lower-educated parents, who were more likely to be at home directly supervising their children [30].

Findings from this study indicate that children with an unintentional injury have higher scores in CBCL than those without injury (p < 0.01). The findings are consistent with recent evidence that children with more (and more severe) behavior disorders are more likely to suffer injury [13, 26, 31]. In general, behavioral disorders are common in school-age children; during this phase of life, children have stable physical development but are more likely to have emotional problems and impulsive behaviors, which could cause them to engage in careless and risky behaviors [32]. School-age children spend lots of time at school, and the faculty members are responsible for their supervision during school hours. However, in China, the ratio between teachers and students is about 1:40 ~ 50, which was highlighted as the main cause for injuries in a previous study [32]. Researchers point out that most children with an unintentional injury had emotional instability when they encountered a hazardous environment [13, 33]. The current study had similar findings, namely that children with more behavior disorders tended to have more injury incidents. Interestingly, girls had more behavior disorders (40.4 %) compared to boys (33.3 %) in the current study; this could be the result of different parenting patterns between boys and girls because Chinese boys are more often punished by their parents when they make mistakes [34–37]. In Chinese culture, parents tend to strictly discipline boys for mistakes or behavior problems, whereas these behaviors would be tolerated (or even rewarded) in girls. This might have the effect of reinforcing behavior disorders in girls [38]. An alternative explanation for this phenomenon could be related to the different scoring systems between genders and the fact that there are higher cut-off points for boys in the CBCL. The appropriateness of using a gender-based scoring system for the CBCL may need to be further explored in Chinese society.

Logistic regression analysis indicates that schizoid, anxiety/depression, and hyperactivity are the significant predictors for injury in boys, while anxiety/depression and delinquent behavior are the predictors for girls. Boys and girls with the above behavior disorders had more than two times greater likelihood of experiencing an unintentional injury than those children who had normal CBCL scores. Anxiety/ depression was a predictor of injury for both boys and girls. This result is different from previous research that showed children with externalizing behavior are more likely to be impulsive and are at great risk for injury [39–41]. However, a recent study revealed that Chinese children with depression or delinquent behaviors were also inclined to have risk behaviors and injuries later in life, including substance abuse, aggression, and suicide [42]. In China, anxiety and depression are very common among school-age children, which could result from a tendency of Chinese parents to overemphasize academic success [43, 44]. For example, a recent study of the effects of stress on school-age children (N = 2,191) indicated that one third of Chinese children who experience psychological problems, particularly anxiety and depression, as a result of academic requirements and parental pressure, are inclined to have injury episodes at home and at school [45].

The current study found that unintentional injuries happened most often at school and at home. This suggests that parents, school teachers, and pediatric health care providers should pay more attention to children who have behavior problems, especially those with hyperactivity, anxiety/depression, and delinquent behaviors. To prevent injury, it is necessary for schools and community health centers to screen children’s behaviors on a regular basis, and parents should be encouraged to seek help when they notice problem behaviors in their youngsters.

This study contributes knowledge to the Chinese medical community on the association between children’s behavioral characteristics and injury events. Specifically, it reveals significant behavioral predictors for injury in school-age children. However, the findings should be considered in light of several methodological limitations. First, children’s behaviors were assessed in the context of unintentional injuries that had occurred within the previous 12 months. Recall bias could occur, in particular for identifying minor injuries because they might be easily forgot, thus threatening the study’s internal validity; therefore, a prospective study is needed. Second, the participants of this study were all mentally healthy children. Children with ADHD and who could be more inclined to have unintentional injuries were excluded, but should be included in future studies to provide a more complete explanation. Third, data on the severity of unintentional injuries was not collected in this study, so the association, if any, between severity of injury and behavior problems could not be determined. Last, the participants were all from five elementary schools in one city (Daqing) and were chosen by convenience sampling; thus, the findings might not be generalizable to other areas of China.

The findings of this study suggest that children with behavioral disorders are more inclined to suffer from unintentional injuries. Behavioral disorders such as schizoid, anxiety/depression, hyperactivity and delinquent behavior could predict unintentional injury. The results support the importance of assessing behavioral characteristics among school-age children and highlight the necessity of doing interventions to assist both parents and their children in managing or reducing behavioral disorders and preventing unintentional injury. Pediatric care providers should learn behavior management strategies to reduce injury risk and seek effective methods to recognize children with behavior disorders for injury prevention efforts. Safety education classes should be offered in schools, and these classes should be adaptable to address the different characteristics of children’s behavior.