Trauma presents a significant public health concern world-wide, as well as in Aotearoa New Zealand, impacting individuals, families and healthcare systems.
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Trauma presents a significant public health concern world-wide,1,2 as well as in Aotearoa New Zealand,3 impacting individuals, families and healthcare systems. Research indicates that certain ethnic groups experience a disproportionate burden of trauma compared to others.4 Māori, as the Indigenous population of Aotearoa New Zealand, have been identified as particularly vulnerable to trauma.5,6,7 Historical and ongoing socio-economic disparities, coupled with cultural factors, contribute to higher rates of injury among Māori communities.6,7 Similarly, Pacific peoples—another significant ethnic group in Aotearoa New Zealand—also experience a higher prevalence of trauma, often linked to socio-economic challenges, cultural norms and lifestyle factors. Ethnic inequalities of trauma incidence in general8 and specific traumatic injury have been observed in several settings.9 In Aotearoa New Zealand, socio-economic and ethnic differences have been noted with respect to trauma incidence10 and specific injuries,6,11 and among different age groups.12 Furthermore, studies have shown variations in trauma patterns and severity across different ethnic groups. For instance, while motor vehicle crashes are a leading cause of injury for Europeans and Asians, interpersonal violence and self-harm are more prevalent among Māori and Pacific peoples.7,13–15 Understanding these nuances is essential for designing culturally appropriate prevention and intervention strategies.
The primary objective of this study is to examine the ethnic variations in trauma hospitalisations in the Te Manawa Taki (TMT) health region of Aotearoa New Zealand. Specifically, we aim to analyse the demographic characteristics of patients hospitalised due to trauma across different ethnic groups and explore disparities in injury severity, outcomes and healthcare utilisation using 10-year data from the TMT Trauma Registry (TMTTR). The TMT health region of Aotearoa New Zealand supports a population of 1,007,405 people, 28% of whom identify as Māori.16,17 The TMT health region has broad demographic characteristics for age groups, ethnicity and rurality that are representative of Aotearoa New Zealand as a whole.5,18,19 This study reports the descriptive epidemiology of trauma patients from different ethnic groups admitted to hospitals across all ages and severities within a health region in Aotearoa New Zealand over a 10-year period.
A retrospective analysis of data from the TMTTR of all ages admitted to TMT hospitals with an injury during the 10-year period from 1 January 2013 to 31 December 2022 was conducted. Ethical approval was provided under the locality authorisation process by the Te Whatu Ora – Health New Zealand Waikato Research Office (RD023079).
TMTTR has been in operation since 2012, covering trauma patient admissions across six hospitals in the region. The registry is designed to capture injury characteristics, interventions and inpatient costs of all trauma admissions.5 The registry follows international standards, and excludes patients who sustained injuries such as insufficiency or peri-prosthetic fractures, exertional injuries, hanging/drowning/asphyxiation without evidence of external force, poisoning, ingested foreign body, injury as a direct result of pre-existing medical conditions or late effects of injury, or if the injury occurred more than 7 days prior to admission.20 The registry collects demographic and injury event information from prehospital records, hospital systems and directly from patients. The cause, place and types of injury are classified using the International Classification of Disease (ICD-10-AM).21
Ethnicity is a self-perceived parameter of cultural affiliation, and people can identify with more than one ethnic group.22,23 As such, the collection and recording of ethnicity in the health and disability sector in Aotearoa New Zealand are guided by the ethnicity protocol of the Ministry of Health (MoH).24 The trauma registry collects and records ethnicity information consistent with this protocol. The MoH also provides population projections for each district health board (DHB) that further classifies into four groups: Asian, Māori, Pacific peoples, and European and other.15 In this study, ethnicity of trauma patients was classified into the four groups consistent with TMT region’s annual population projections, which were provided by the MoH to Te Whatu Ora – Health New Zealand Waikato (DHB population projections 2018 update). Additionally, injury event information, type, intent, cause and place of injuries, hospital length of stay (LOS) and outcomes were also taken into account. The intent of injury was categorised as unintentional, by other or self-inflicted as per the ICD-10-AM. Hospital LOS was calculated at an event level considering the duration of stay at each hospital admission from arrival date–time to discharge date–time at each facility, summed at a patient level. The case fatality rate was calculated by taking into account the proportion of trauma patients who died while in the hospital. It only includes deaths resulting directly from their injuries and excludes “medical deaths” related to non-traumatic disease. The Abbreviated Injury Score (AIS)25 was used to quantify injury patterns, and the Injury Severity Score (ISS) was assigned based on AIS version 2015. The ISS scores from all years using the 2008 version have been mapped to the 2015 version using an R script for TMTTR data extracts reported to the National Major Trauma Registry (NMTR). To analyse injury severity, the trauma ISS was classified into high (ISS >12),26 moderate (ISS 9–12) and low (ISS 1–8) severity to show the variation in patients’ characteristics in the transition from the larger “non-Major” trauma group to “Major” as defined in the NMTR.27 The data were extracted from the TMTTR using DI Writer/CollectorTM, and all statistical analyses were performed using RStudio v 4.3.1. Analysis is presented as counts, percentage and rates.
From 1 January 2013 to 31 December 2022, 60,753 trauma patients were admitted to hospitals within the TMT region. Of these, 39,291 (64.7%) were European and other ethnic group, 18,015 (29.7%) were Māori, 1,998 (3.3%) were Asian and 1,411 (2.3%) were Pacific peoples. The demographic characteristics of these patients are shown in Table 1. Regardless of ethnicity, males had higher hospitalisation rates for any trauma than females. Rates were higher for Māori and Pacific men.
View Table 1–6, Figure 1.
Overall, there is a significant difference in incidence rates (p<.001) between the Asian and the European and other groups, as well as between the Māori and the European and other groups, with Māori having the highest rate (Table 2). The population-adjusted incidence rates for Asians are significantly lower than European and other for all severity injury scores across the ISS 1–8, ISS 9–12 and ISS >12 bands. Incidence rates of all severities are not significantly different between the European and other group and Pacific peoples.
The annual incidence of all ethnicities has been variable over the study period, with a drop in 2018 (Figure 1), particularly among Pacific peoples. In 2022, the incidence per 100,000 population was found to be 208 for Asian, 776 for Māori, 642 for European and other and 597 for Pacific peoples. A decline in incidence can be seen since 2020 for all ethnic groups except Māori. From 2020 to 2022, the incidence per 100,000 declined by 58 for Asian, 56 for European and other and 79 for Pacific peoples. Among Māori, the incidence fluctuated over these 2 years, with a small increase of 4 in 2021, followed by a decline of 76 in 2022. The non-overlaps of confidence interval for Asians’ trauma incidence suggest a significant difference between incidences of Asians with the other ethnic groups.
Regardless of ethnicity, falls and road traffic crashes were among the top three causes of all severities (Table 3). The top three causes cover 60% of all events for Asian, 55% for Māori, 54% for Pacific peoples and 58% for European and other. The leading cause of severe trauma for all ethnic groups, except for European and other, was road traffic crashes. However, for the European and other group, falls were the primary cause. Falls were the most common cause of injury among patients with moderate- and low‑severity trauma, regardless of ethnicities. Among Māori and Pacific peoples, assault was one of the top three causes of injury.
The leading place of injury resulting in hospitalisations of all severities combined was home for all ethnic groups (Table 4). Regardless of ethnicity, street and highways were the leading place of injury for high-severity trauma, while homes were the primary location of low-severity admissions. The primary location of moderate trauma varied among different ethnic groups. For Asian and Māori, it was street and highway, while for Pacific peoples and European and other it was home.
For all ethnic groups except the European and other group, there were slightly more penetrating injuries among severe trauma compared to other severity groups (Table 5). The blunt injuries were slightly high in moderate trauma, while the burn injuries were slightly high in low-severity trauma across all ethnic groups. Proportionately more injuries were caused by the injury intent category labelled “others” in the high-severity group than in the low- and moderate-severity groups for all ethnicities. Self-inflicted injuries were more common in low‑severity hospitalisations among all ethnic groups except Asian.
Table 6 shows that Asian patients had a higher average LOS of 11 days for high-severity trauma across 2013–2022 compared to other ethnic groups. In contrast, the LOS for moderate- and low‑severity trauma was relatively similar across all ethnic groups except for European and other. High‑severity trauma events had the highest case fatality rate (CFR) of 7% for European and other compared with a CFR of 5% for Māori and Asian and a CFR of 4% for Pacific peoples. Pacific peoples had the lowest or no (for moderate) CFR across all ISS bands compared to other ethnicities.
Ethnic disparities in trauma hospitalisations in Aotearoa New Zealand highlight significant public health concerns tied to broader social and economic inequities. This study is the first to detail the epidemiology of trauma patients across ethnic groups admitted to hospitals of all ages and severities in a specific health region over 10 years.
Notable differences in incidence rates were found, with Māori experiencing the highest rates and Asians the lowest. Literature indicates that socio-economic status may be a key factor driving these disparities.7,9,28,29 Māori populations in Aotearoa New Zealand often face socio-economic disadvantages, including lower income, poorer housing and limited access to education and healthcare.12,28 These factors can elevate trauma risk through unsafe working conditions, inadequate housing and limited access to preventive healthcare.28,30
Study results show a decline in incidence since 2020 for all ethnic groups except Māori, likely due to reductions in injury-related hospitalisations during the COVID-19 pandemic,31,32 which may have affected marginalised communities differently.8 The fewer penetrating injuries among severe trauma for the European and other group possibly reflect generally higher socio-economic status, granting access to safer neighbourhoods with less violence.7,29 Falls and traffic crashes were among the top three causes of all severities, with falls being the primary cause for moderate- and low-severity trauma. Assault was one of the top three causes of injury among Māori and Pacific peoples, consistent with existing literature.5,11–14,18
The higher average LOS for high-severity trauma among Asians could be related to socio-cultural factors. The European and other group had a high average LOS for moderate- and low-severity trauma. The findings suggest that the increased admission volumes for moderate- and low-severity trauma were the main reason for the higher average LOS of the European and other group when compared to the other ethnic groups.
Study revealed that Pacific peoples had the lowest or no (for moderate) CFR across all ISS bands compared to other ethnic groups. In contrast, Asians had a higher CFR for moderate-severity trauma that could be due to the same socio‑cultural factors leading to a higher LOS. The factors contributing to mortality and survival outcomes in moderate- and low-severity trauma need further study in exploring trauma injury care practices of different ethnic groups.
As the study presents the findings of cumulative 10-year data, it limits identifying changes of injury characteristics over time. Furthermore, the classification of European and other as one group tends to overlook some other ethnic groups, such as Middle Eastern, Latin American and African ethnicities. Future studies may explore the minority ethnic groups to identify injury parameters. Another inherent limitation is the accuracy of the ethnicity data in healthcare systems, including trauma registries. Previous studies have reported significant variation between self-identified ethnicity and recorded ethnicity in the hospital systems,33,34 which is further complicated by people shifting their ethnicity identity over time.23 However, as this study uses a large dataset of over 60,000 records and uses four groups of ethnicity, it allows for drawing reasonable conclusions at aggregate levels.
Addressing ethnic disparities in trauma hospitalisations in Aotearoa New Zealand requires a multifaceted approach that encompasses upstream interventions to address socio-economic inequalities, culturally sensitive healthcare delivery, targeted injury prevention strategies and efforts to address systemic biases within the healthcare system. Collaboration between healthcare providers, policymakers, community organisations and ethnic communities is essential for developing effective interventions to reduce these disparities.
Over the 10-year study, annual trauma incidence varied slightly among different ethnic groups, with a notable decline in 2018. Noteworthy disparities were observed, with Māori exhibiting the highest rates and Asians the lowest. Falls and road traffic crashes consistently ranked among the top three causes of injuries across all severity levels. This study has illuminated the ethnic inequities in traumatic injury hospitalisations, paving the way for targeted interventions to reduce the injury burden on vulnerable populations. Ultimately, addressing these disparities aligns with broader efforts to promote health equity and ensure optimal health outcomes for all residents of Aotearoa New Zealand.
To examine the ethnic variations in trauma hospitalisations in a health region of Aotearoa New Zealand over a 10-year period.
A retrospective, observational study utilised data from the Te Manawa Taki (TMT) regional trauma registry to identify individuals of all ages and injury severities who were hospitalised due to injuries between 2013 and 2022. This investigation focusses on the epidemiology of trauma, examining factors such as ethnicity, gender, Injury Severity Score (ISS) and injury characteristics.
In the TMT region, out of the 60,753 trauma patients admitted to hospitals, the distribution across ethnic groups was as follows: 39,291 (64.7%) were European and other ethnic group, 18,015 (29.7%) were Māori, 1,998 (3.3%) were Asian and 1,411 (2.3%) were Pacific peoples. Notably, there were significant differences in incidence rates among these groups, with Māori exhibiting the highest rate. Moreover, males were more predisposed to hospitalisation due to trauma compared to females. This gender discrepancy was consistent across all ethnicities.
Regardless of ethnicity, falls and road traffic crashes emerged as leading causes of trauma across all severity levels. Additionally, the primary location of injury varied depending on the severity of trauma. For high-severity cases, street and highways were the predominant sites, whereas homes were more commonly associated with low-severity admissions.
The study examines the incidence, demographic characteristics, severity and outcomes of trauma patients across various ethnic backgrounds admitted to hospitals within the TMT region of Aotearoa New Zealand over a decade. The disparities in injury rates among different ethnic groups underscore the substantial strain on the healthcare system. Pinpointing high-risk demographics and recognising these disparities will be instrumental in devising targeted prevention measures, enhancing access to culturally sensitive trauma services and advancing health equity.
Ishani Soysa: Research Manager, Te Manawa Taki Trauma Research Centre, Te Whatu Ora – Health New Zealand Waikato, Hamilton, Aotearoa New Zealand.
Sheena Moosa: Research Fellow, Te Manawa Taki Trauma Research Centre, Te Whatu Ora – Health New Zealand Waikato, Hamilton, Aotearoa New Zealand.
Grant Christey: Clinical Director, Te Manawa Taki Trauma System, Te Whatu Ora – Health New Zealand Waikato, Hamilton, Aotearoa New Zealand; Honorary Associate Professor, Faculty of Medical and Health Sciences, Surgery, University of Auckland, Aotearoa New Zealand.
A/Prof Grant Christey: Clinical Director, Te Manawa Taki Trauma System, Meade Clinical Centre, Waikato Hospital, Hamilton; Honorary Associate Professor, Faculty of Medical and Health Sciences, Surgery, University of Auckland, Aotearoa New Zealand.
The authors declare no competing interests.
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