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Causes and characteristics of injury in paediatric major trauma and trends over time
  1. Ben Beck1,
  2. Warwick Teague2,3,4,
  3. Peter Cameron1,5,
  4. Belinda J Gabbe1,6
  1. 1 Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
  2. 2 Trauma Service, The Royal Children’s Hospital, Melbourne, Victoria, Australia
  3. 3 Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
  4. 4 Surgical Research Group, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
  5. 5 Emergency and Trauma Centre, The Alfred Hospital, Melbourne, Victoria, Australia
  6. 6 Farr Institute, Swansea University Medical School, Swansea University, Swansea, UK
  1. Correspondence to Dr Ben Beck, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne VIC 3004, Australia; ben.beck{at}monash.edu

Abstract

Objective To investigate causes, characteristics and temporal trends of paediatric major trauma.

Design A retrospective review of paediatric major trauma (<16 years of age) was conducted using data from the population-based Victorian State Trauma Registry from 2006 to 2016. Temporal trends in population-based incidence rates were evaluated using Poisson regression.

Setting Victoria, Australia.

Results Of the 1511 paediatric major trauma patients, most were male (68%), had sustained blunt trauma (87%) and had injuries resulting from unintentional events (91%). Motor vehicle collisions (15%), struck by/collisions with an object or person (14%) and low falls (13%) were the leading mechanisms of injury. Compared with those aged 1–15 years, a greater proportion of non-accidental injury events were observed in infants (<1 year) (32%). For all patients, isolated head injury (29%), other/multitrauma (27%) and head and other injuries (24%) were the most prevalent injury groups. The incidence of paediatric major trauma did not change over the study period (incidence rate ratio (IRR)=0.97; 95% CI 0.92 to 1.02; p=0.27), which was consistent in all age groups. There was a 3% per year decline in the incidence of transport events (IRR=0.97; 95% CI 0.94 to 0.99; p=0.005), but no change in the incidence of falls of any type (IRR=1.01; 95% CI 0.97 to 1.04; p=0.70) or other events (IRR=1.00; 95% CI 0.97 to 1.02; p=0.79). The overall in-hospital mortality rate was 7.2%.

Conclusions This study demonstrated no change in the incidence of paediatric major trauma over an 11-year period. Given the potential lifelong impacts of serious injury in children, additional investment and coordination of injury prevention activities are required.

  • injury prevention
  • epidemiology

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What is already known on this topic?

  • Injury is a significant cause of morbidity and mortality in children and adolescents.

  • Epidemiological studies are essential for informing and evaluating injury prevention strategies and also for monitoring changes over time.

What this study adds?

  • In this population-based study, the incidence of paediatric major trauma did not change over an 11-year period.

  • With increasing age, the proportion of events resulting from low falls decreased, while the proportion of events resulting from motorcycle and pedal cycle collisions increased.

  • Non-accidental injury events were most prevalent in infants.

Introduction

Globally, injury is a leading cause of death and disease burden in children and adolescents.1 In Australia, the cost of child injury hospitalisations totals more than $200 million every year.2 Furthermore, injuries in children and adolescents can result in significant and lifelong impacts on health and well-being.3 4

Despite the significant consequences of paediatric trauma for both the patient and their family, there are relatively few population-based studies of the epidemiology of paediatric trauma when compared with adults, particularly in the setting of major trauma. Most cohort studies of paediatric trauma are limited to short time frames that do not facilitate investigation of trends over time,5–7 are single-centre studies8 or are limited to specific injury types, such as traumatic brain injury,9 or causes of injury.10 The exception is a study from Mitchell et al 2 which reported no change in the incidence of child injury hospitalisations in Australia from July 2002 to June 2012. These studies are essential for informing and evaluating injury prevention strategies and also for monitoring trauma systems and changes over time. However, such studies are currently absent in the paediatric major trauma population. Furthermore, current data are required to identify whether an absence of a change in the incidence of paediatric trauma has persisted.

As paediatric major trauma patients have been shown to have marked quality of life deficits at 24 months after injury,11 there is a particular need to understand causes and characteristics of injury in this cohort, and how this is changing over time. This is necessary to develop injury prevention strategies that target causes of injury that result in the most severe injuries and have the most significant impacts on a child’s health and well-being. Using a population-wide, comprehensive registry, the aim of this study was to investigate causes, characteristics and temporal trends of paediatric major trauma over an 11-year period.

Methods

Study design

A retrospective review of paediatric major trauma was conducted using data from the population-based Victorian State Trauma Registry (VSTR) from 1 January 2006 to 31 December 2016.

Setting

The state of Victoria, Australia (population 6.1 million), implemented the Victorian State Trauma System between 2000 and 2003.12 The Victorian State Trauma System is a centrally coordinated trauma network with one paediatric and two adult major trauma services. A single ambulance service provides road and air (fixed wing and helicopter) transport of patients. Within this system, ‘paediatric’ is defined as <16 years of age.

Study population

Paediatric major trauma patients were identified from the VSTR. The VSTR is a population-based registry that collects data about all hospitalised major trauma patients in Victoria.13 The VSTR collects data from the prehospital and acute care hospital phases, including in-hospital mortality, for all cases. A case is included in VSTR if any of the following criteria are met: (1) death due to injury; (2) an Injury Severity Score >12 as determined by the Abbreviated Injury Scale (AIS) (2005 version 2008 update); (3) admission to an intensive care unit (ICU) for more than 24 hours and requiring mechanical ventilation for at least part of their ICU stay; and (4) urgent surgery. Major trauma events occurring outside Victoria, and subsequently transported to Victorian hospitals for care, were excluded from this study.

Procedures

Demographic factors, injury event, injury type and severity, and other relevant factors were extracted from the registry. The comorbid status of the patient was defined using the Charlson Comorbidity Index (CCI), where International Classification of Diseases 10th Revision-Australian Modification (ICD-10-AM) codes for associated conditions were mapped to the CCI.14–16 A score of 0 represents no serious coexisting conditions. Postcodes of residence were mapped to the Accessibility/Remoteness Index of Australia (a geographical index of remoteness) and the Index of Relative Socioeconomic Advantage and Disadvantage (which ranks areas in Australia according to relative socioeconomic advantage and disadvantage). Cases were considered compensable if the fund source for their hospital admission was either the third party, no-fault insurer for transport (Transport Accident Commission) or work (Victorian WorkCover Authority) injury. Intent of injury was stratified as unintentional, intentional self-harm and non-accidental injury. Specific characteristics of fall-related paediatric major trauma were characterised using the ICD-10-AM external cause codes (W01–W96). Head injury was classified as an AIS severity score of the head greater than 3 and spinal cord injury was classified according to an AIS severity score of the spine greater than 3. For extremity, neck, face, thorax, abdominal and external injuries, an AIS severity score greater than 2 was used to identify the presence of a significant injury in that body region. These cut-offs were used to allocate cases to six broad injury groups.

Data analysis

Patient age was categorised: 0 to <1 (described herein as infants), 1–5, 6–10 and 11–15 years. Population-based incidence rates and 95% CIs were calculated for each financial year based on the total population on 30 June for the years 2006–2016. Poisson regression was used to determine whether the incidence rate increased or decreased over the study period. A check for potential overdispersion of the data (variance greater than the mean) was performed to ensure that the assumptions of a Poisson distribution were met. The incidence rate ratio (IRR) and 95% CIs were calculated. Due to small numbers in some specific causes of injury, incidence calculations by cause of injury were stratified by transport, falls of any type, or other. Comparisons between patient age groups were made using the χ2 test and the Mann-Whitney U test, as appropriate. Data analysis was performed using Stata (V.14.2, StataCorp, College Station, TX). A p value <0.05 was considered statistically significant.

Results

Over the 11-year study period, there were 1511 paediatric major trauma patients (aged <16 years). The demographic and clinical characteristics of the study population are reported in table 1. Most patients were male (68%), had sustained blunt trauma (87%) and had injuries resulting from unintentional events (91%). Most injuries occurred in the home (32%) or on a road, street or highway (33%), while a further 11% occurred in a place for recreation, 6% at school, 6% at an athletics or sports area and 6% on farms. Motor vehicle collisions (15%), struck by/collisions with an object or person (14%) and low falls (13%) were the leading mechanisms of injury. Of all paediatric major trauma cases, high falls accounted for 10%, horse-related events accounted for 4% and quad bike events accounted for 1%. Peaks in the count of major trauma patients were observed in infants and in young teens (13–15 years) (figure 1).

Figure 1

Counts of paediatric major trauma patients by year of age.

Table 1

Demographic and injury event details. Data are presented for all paediatric cases (aged <16 years) and stratified by age group

Differences between age groups were noted for the cause (figure 2), intent, activity and place of injury (table 1). Compared with those aged 1–15 years, a greater proportion of non-accidental injury events were observed in infants (32%). Intentional self-harm events were observed in the greatest proportion in those aged 11–15 years (3%). In infants, low falls (32%) and being struck by/collision with an object or person (22%) were the leading mechanisms of injury. With increasing age, the proportion of events resulting from low falls decreased, while the proportion of events resulting from motorcycle and pedal cycle collisions increased (figure 2). Fire, scalds and contact burns were observed in greatest number in those aged 1–5 years (table 1). The majority of injury events in infants occurred in the home (81%), and this proportion declined with increasing age (table 1). Consistent with the mechanisms of injury, a road, street or highway was the most prevalent place of injury for those aged 6–10 years (40%) and 11–15 years (39%). Men were consistently over-represented in all age groups (table 1).

Figure 2

Causes of injury by age group. MVC, motor vehicle collision.

Falls of any type accounted for 23% of all paediatric major trauma (table 2). These included falls from, out of, or through a building or structure (2.8%); falls involving ice skates, skis, roller skates, skateboards, scooters and other pedestrian conveyances (2.8%); falls involving playground equipment (2.5%); and falls by being carried or supported by another person (2.4%). Proportional differences in causes of fall-related injury were observed between age groups. Specifically, infants had greater proportions of falls while being carried or supported by other persons, while falls involving playground equipment were greatest in those aged 1–5 and 6–10 years (table 2).

Table 2

Characteristics of fall-related paediatric major trauma presented as overall and by age group

Profile of injury

For all paediatric major trauma patients, isolated head injury (29%), other/multitrauma (27%) and head and other injuries (24%) were the most prevalent injury groups (table 3). Differences were observed between age groups, with the proportion of patients with isolated head injury greatest in infants (63%) (table 3).

Table 3

Profile of injury presented as overall and by age group

Temporal trends

The incidence of paediatric major trauma did not change over the study period (IRR=0.97; 95% CI 0.92 to 1.02; p=0.27). This was consistent in those aged <1 year (IRR=0.97; 95% CI 0.93 to 1.02; p=0.23), 1–5 years (IRR=0.97; 95% CI 0.92 to 1.03; p=0.38), 6–10 years (IRR=0.94; 95% CI 0.88 to 1.00; p=0.06) and 11–15 years (IRR=0.99; 95% CI 0.95 to 1.04; p=0.66) (figure 2). There was a 3% per year decline in the incidence of transport events (IRR=0.97; 95% CI 0.94 to 0.99; p=0.005), but no change in the incidence of falls of any type (IRR=1.01; 95% CI 0.97 to 1.04; p=0.70) or other events (IRR=1.00; 95% CI 0.97 to 1.02; p=0.79). Crude incidence rates are provided in the online supplementary material.

Supplementary file 1

Outcomes

The overall in-hospital mortality rate was 7.2% (n=109). This was higher in those aged 1–5 years (14.3%) compared with infants (8.5%) and those aged 6–10 years (4.9%) and 11–15 years (3.7%).

Discussion

We investigated causes, characteristics and temporal trends of paediatric major trauma over an 11-year period. Between 2006 and 2016, there was no change in the incidence of paediatric major trauma. Unintentional injury accounted for more than 90% of events, with distinct age group profiles of injury that were aligned to the stages of childhood development.

Consistent with studies in Australia2 and internationally,5 7 8 we observed significant differences in causes of injury between age groups. Specifically, low falls and being struck by or colliding with an object or person were the leading causes of injury in infants, while the proportion of events resulting from motorcycle and pedal cycle events increased with increasing age. These age-related differences are consistent with stages in childhood physical, cognitive and social development. With each developmental stage, improvements are observed in physical capacity, such as height, reach, strength and dexterity, and executive functions, such as attentional control and information processing.17 As a result, children become better at being able to modify behaviour to reduce injury risk. However, at the same time, increased independence and skill acquisition also increase injury risk. This is demonstrated by peaks in injuries in infants and young teens (figure 1).

To our knowledge, this is the first population-based study to investigate temporal trends in paediatric major trauma. Over an 11-year period, we observed no change in the incidence of paediatric major trauma. This is supported by similar findings of no change in the incidence of all child injury hospitalisations in Australia2 and emergency department visits in Sweden.8 While we observed no change in the incidence of paediatric major trauma resulting from falls of any type or other events, we noted a 3% per year decline in the incidence of transport events. This suggests, in the absence of a change in exposure, that injury prevention efforts in road safety may have reduced injury rates. One notable legislative change during the study period was the introduction of new national child restraint laws in 2010 that required children aged up to 7 years to be restrained in a dedicated child restraint (previously up to 1 year of age). This resulted from evidence demonstrating the injury risk associated with premature graduation of children to adult seat belts.18 19

All of these paediatric major trauma events are preventable. Given that injury rates overall have not changed over time, the significant healthcare costs and the potential lifelong impacts of these injury events, it is clear that enhanced injury prevention and safety promotion activities are required. To achieve the goal of eliminating serious injury in children, a multifaceted and coordinated response is required. This paper enables us to target injury prevention activities to address the identified causes of injury. However, these events are often complex and multifactorial. In Australia, there is no current national injury prevention strategy or plan, and it has been suggested that a multisectorial and nationally coordinated approach to childhood injury prevention and management is needed to reduce the burden of childhood trauma.2

Across the spectrum of legislation and enforcement, product modification, safety devices and education, numerous interventions have been shown to reduce childhood injury. These include seat belt, child restraint and helmet laws, reduced speeds around schools, residential areas and play areas, swimming pool fencing, standards for playground equipment, toys and packaging, smoke alarms and child-resistant containers.20 Given that the majority of paediatric major trauma resulted from unintentional events (91%), additional efforts to reduce unintentional injury are clearly needed. However, amid rising childhood obesity levels,21 there is a need for continued promotion of physical activity in children.22 Injury prevention strategies must not restrict access for children to engage in physical activity, but rather provide them with an environment to safely do so.

Both intentional self-harm and non-accidental injury are very important considerations in paediatric trauma. Our results demonstrated that non-accidental injury accounted for 32% of major trauma in those aged less than 1 year. Non-accidental injury commonly results from assault from a parent or neglect and is more prevalent in low socioeconomic areas.23 24 Targeted parental education and support are warranted, in addition to enhanced efforts for early identification of parents who are considered at risk of being perpetrators of abuse.24 25

The strengths of this study are the use of the high-quality, population-based VSTR, allowing a comprehensive overview of all paediatric major trauma. However, prehospital trauma deaths were excluded from this analysis, and there may be temporal changes in causes of injury for prehospital trauma deaths that we were unable to account for in this study. However, the annual number of paediatric prehospital trauma deaths in our region is low.26 Additionally, due to small numbers in specific causes of injury, we were not able to investigate temporal trends in specific causes of injury. Furthermore, it is important to note that major trauma is the tip of the injury iceberg, and numbers of all child injury hospitalisations are significantly greater than the cohort we report on in this study. Regardless, our findings are consistent with that reported for all child injury hospitalisations.2

Conclusion

Over an 11-year period, we observed no change in the incidence of paediatric major trauma. Given the potential lifelong impacts of these events on a child and their family, there is a clear need for enhanced injury prevention activities. All of these injury events are preventable and additional investment in combination with coordinated and targeted injury prevention activities is required to achieve the goal of eliminating serious injury in children.

Acknowledgments

The Victorian State Trauma Registry (VSTR) is a Department of Health and Human Services, State Government of Victoria and Transport Accident Commission funded project. The Victorian State Trauma Outcome Registry and Monitoring (VSTORM) group is thanked for the provision of VSTR data. The authors also thank Sue McLellan and Monica Perkins.

References

Footnotes

  • Contributors All authors contributed to the conception of the study. BB conducted the analysis and wrote the first draft. WT, PC and BJG all provided critical editorial input.

  • Funding The Victorian State Trauma Registry (VSTR) is a Department of Health and Human Services, State Government of Victoria and Transport Accident Commission funded project. BB was supported by an Australian Research Council Discovery Early Career Researcher Award Fellowship (DE180100825). WT’s role as Director of Trauma Services at The Royal Children’s Hospital, Melbourne, is supported by a grant from the Royal Children’s Hospital Foundation. PC was supported by a National Health and Medical Research Council (NHMRC) Practitioner Fellowship (545926). BJG was supported by an Australian Research Council Future Fellowship (FT170100048).

  • Competing interests None declared.

  • Patient consent Not required.

  • Ethics approval The VSTR has Human Research Ethics Committee approval from the Department of Health and Human Services (DHHS) for all 138 trauma-receiving hospitals in Victoria, and the Monash University Human Research Ethics Committee (MUHREC).

  • Provenance and peer review Not commissioned; externally peer reviewed.

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