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Globally, traumatic brain injury (TBI) is the foremost cause of death and disability in both children and young adults.[[1,2]] New Zealand is no exception, with an incidence rate in 2010–2011 of 790/100,000 observed in Hamilton City and Waikato District.[[2]] At this time, TBI was more prevalent in males, 0–34-year-olds, Māori and those living in rural areas, with falls, exposure to mechanical forces, transport incidents and interpersonal violence recognised as important causes.[[2]]

Traumatic brain injuries are significant in number, diverse in nature with a severity range from mild concussion and moderate brain oedema, haematoma and/or haemorrhage, to severe crush or penetrating injury causing extended loss of consciousness.[[3,4]] TBI also commonly occur with other concomitant injuries requiring additional assessment, treatment and rehabilitation.[[3,4]] Accordingly, TBI can temporarily or permanently affect cognitive, behavioural, emotional and physical aspects of quality of life, including the ability to live independently, maintain relationships and return to work, education or leisure activities.[[6–8]] Early, equitable and coordinated management is therefore essential to optimise outcomes.

Although the incidence, at-risk populations and common causes of TBI were identified in New Zealand a decade ago[[2]], less is known about the patient journey through the TMT hospital setting of patients who are admitted with a diagnosis that includes TBI. The TMT Trauma Registry (TR) contains data to enable evaluation of demographics, injury complexity, utilisation of hospital resources and discharge destinations for individuals admitted to acute care facilities in the region. Such information assists quantification of the burden of hospitalised TBI on affected individuals, their families/whānau and regional health systems. It will also assist identification of issues pertaining to clinical service provision and rehabilitation pathways. Anecdotal evidence pointed to an increasing volume of TBI related injury across the region.

The aim of this study is to investigate not only the volume and demographic features of patients, but also processes of care, injury events, injury types and treatment and resource allocation of TMT residents hospitalised with a TBI.

The TMT region encompasses five district health boards (DHB) and displays demographic characteristics reflective of New Zealand for median age (35 vs 38 years) and gender (48% male) and a higher proportion of Māori (26.5% vs 15.7%).[[9]] The average regional population during the study period was 909,109, with an average annual population increase of 2.0%. Providing tertiary care to the region Waikato Hospital is a Royal Australasian College of Surgeons verified Level 1 Trauma Centre,[[10]] with specialist teams and resources to manage all acute major and non-major trauma. TBI rehabilitation options in the region include non-specific inpatient wards and DHB and Accident Compensation Corporation (ACC) contracts in the outpatient, community and home-based settings.

Methods

A retrospective review of the TR was conducted from 1 January 2012 to 31 December 2019. The TR collects comprehensive data on all trauma patients across the region admitted to hospital, within seven days of injury. All patients with TBI were defined and identified by use of the 137 Abbreviated Injury Scale (AIS)[[3]] codes from body region 1 (cranium and brain) defining injury to and around the brain parenchyma. Exclusions included injuries to cranial and spinal nerves, vascular structures and bone in the absence of brain parenchymal disruption. Consistent with other trauma registries, exclusions included insufficiency or peri-prosthetic fractures, exertional injuries, hanging, near drowning or asphyxiation and injuries that occur as a result of a pre-existing medical condition.

Severity of TBI was determined by AIS score, ranging from 1 (minor, 0% threat to life) through to 6 (maximum, 100% threat to life). In accordance with recommendations[[10]] and other trauma registry studies,[[12–14]] TBI was defined as mild, moderate or severe by AIS severity scores of 1–2, 3–4 and ≥5, respectively. Isolated TBI were defined when no other anatomic region had an AIS score. The Injury Severity Scale (ISS)[[15]] standardises injuries sustained in a single incident with thresholds set at ISS≥13 for major and ISS≤12 for non-major.[[16]] ISS scores are calculated from the square of the highest AIS scores from a maximum of three body systems. We determined the contribution of TBI to ISS scores as a proportion (%) to provide an indication of the severity of TBI to multi-trauma patients.

Hospital resource allocation characteristics including surgical procedures and admission to intensive care were categorically coded. Surgical procedures that have a direct impact on brain parenchyma were identified by International Classification of Disease (ICD-10-AM)[[17]] codes (n=34). Length of hospital stay was calculated as mean (SD) and median (IQR). In addition to final discharge destinations from TMT hospitals, all transfers to out-of-region facilities during each patient’s journey were also recorded.

Populations were estimated from Stats NZ census data.[[9]] Ethnicities were categorised as Māori, European and Other according to Stats NZ classifications. Mechanism of injury was classified by the ICD-10-AM[[17]] and grouped by unintentional falls, transport incidents (traffic and non-traffic related), interpersonal violence, exposure to external forces and other causes. Descriptive analyses were performed in Excel (Microsoft Office Professional Plus 2016) and data are presented as number (%), except when outlined as mean (SD) and median (IQR). Ethical approval was deemed out of scope by the New Zealand Health and Disability Ethics Committee and project approval was provided following locality assessment by Waikato DHB and the Māori Research Review Committee (RD21026).

Results

Across the eight-year study period, 4,875 TMT residents were hospitalised with a diagnosis that included TBI, with an average of 609 per year. Figure 1 highlights the increasing trend (R[[2]]=0.833) with an average annual increase of 7.0% and 248 (152%) more TBI-related hospitalisations in 2019 compared to 2012. A further 490 non-domiciled patients were also hospitalised at a TMT facility for an injury that included a diagnosis of TBI but are excluded from analyses.

Figure 1: Count of hospitalisations that included a traumatic brain injury diagnosis by year in Te Manawa Taki residents.

TBI-related hospitalisations were dominated by males (66.4%), Europeans (61.3%) and by age groups 15–34 (30.7%) and 35–64 (25.3%). However, as a percentage of the respective sub-populations, Māori had 33.4% more TBI-related hospitalisations than Europeans, and age groups 0–4 (211%) and 15–34 (184%) had more TBI-related hospitalisations than 35–64-year-olds. Transport incidents and falls were the causes for 79.2% of all TBI-related hospitalisations. Falls were particularly important in those aged 0–4 and ≥65. Interpersonal violence was a notable mechanism in males, Māori and 35–64-year-olds. Severity of TBI did not appear to be influenced by the cause of injury, with transport incidents, falls and interpersonal violence similarly represented across all grades of severity in TBI-related hospitalisations (Table 1).

The majority (72.1%) of TBI diagnoses were classified mild by AIS severity score. Of these, 25.0% were isolated TBI, 10.9% had major ISS scores, 6.4% were admitted to intensive care units (ICU) and 22.2% received surgery. Of the sample, 22.6% of TBI diagnoses were classified as moderate and 12.1% had an isolated TBI, 60.2% had major ISS scores, 32.3% were admitted to ICU, 7.2% required brain surgery, 32.3% received other surgical intervention and 6.5% died as a result of their injuries. Of the remaining 260 patients (32.5 per year) classified with severe TBI, 21.2% were isolated TBI, all had major ISS scores, 56.2% were admitted to ICU, 33.5% required brain surgery, 41.9% received other surgical interventions and 35.0% died. The mean and median percent contribution of the TBI diagnosis to the total ISS score was greater than 50% across the whole sample and within each severity group, although wide variation existed. Wide variability in mean and median length of hospital stay was also evident for the total sample and across each severity group. In those who survived, 1.6% of mild, 18.6% of moderate and 43.8% of severe TBI patients travelled to out-of-region specialised services for brain and/or spinal rehabilitation (Table 2). Non-availability of a rehabilitation facility bed was cited as an impediment to timely hospital discharge for 19 patients, with delays ranging from 1–17 days. This is considered an under-estimation as the impediment to discharge variable is not always recorded in the TR.

Inter-facility transfers occurred on 1,118 occasions across the 4,875 patients (Table 3). This number excludes initial admissions to non-TMT facilities where incidents occurred to residents outside of the TMT region and is possibly further under-estimated by the inability of the TR to capture direct transfers from out-of-region acute care facilities to out-of-region rehabilitation facilities. Of the recorded inter-facility transfers, 801 (16.4%) patients were transferred once, 142 (2.9%) twice, eight (0.2%) three times and two ≥4 times to receive necessary care. Transfers commonly occurred between the smaller regional hospitals and Waikato Hospital, the Level 1 Trauma Centre. However, 41.9% (468/1,118) of all inter-facility transfers were to designated out-of-region acute care and rehabilitation centres, equating to an average of 48 adults and 11 children per year. Of the 4,694 patients who survived, home was the most common discharge destination (82.1%) captured by the TR. The remainder were discharged to regional hospitals for rehabilitation (3.6%) or continuing and convalescence care (1.9%), aged care or nursing home not usual residence (2.0%) and out-of-region facilities (8.0%). A further 1.5% left against medical advice.

Table 1: Number of hospitalised traumatic brain injuries by mechanism of injury and demographics in Te Manawa Taki residents (2012–2019). View Table 1.

Table 2: Hospitalisation and health service characteristics by severity of traumatic brain injury in Te Manawa Taki residents (2012–2019). View Table 2.

Table 3: Journey of care pathway of Te Manawa Taki residents hospitalised with a traumatic brain injury (2012–2019). View Table 3.

Discussion

This study provides comprehensive information on domiciled residents in the TMT region who were admitted to hospital with a diagnosis that included TBI. The 7.0% average annual increase in TBI-related hospitalisations, which is higher than the 2.0% average annual population growth, is a major concern for funding, budgeting and resource allocation. The 152% increase in TBI-related hospitalisations between 2012 and 2019 also indicates a rising incidence despite currently established TBI prevention initiatives.[[6]]

In 2010–2011, a prospective TBI investigation of domiciled Hamilton City and Waikato District residents was conducted.[[2]] During the 12-month study, 882 patients with TBI were admitted to Waikato Hospital. This figure is higher than our observations of 479–765 TBI-related hospitalisations per year from the TMT region, and definition differences explain this discrepancy. We defined hospitalisation by admission to an inpatient bed and by death that occurred in the emergency department, whereas the earlier study[[2]] referred to site of case detection by the study team (hospital, family doctor or other), meaning emergency department presentations with or without subsequent admission to an inpatient bed were included. Further, we diagnosed TBI by the AIS which uses radiological and surgical findings to determine anatomical injury to the brain. Conversely, the earlier study[[2]] functionally defined TBI by the presence of confusion or disorientation and/or loss of consciousness and/or post-traumatic amnesia and/or other neurological abnormalities. Nevertheless, regardless of the requirement for hospital admission, the increasing volume of TBI we observed suggests the burden on regional residents and the health system is increasing.

The higher population-based percentage of hospitalisations for males, Māori and those aged 0–4- and 15–34-years-old aligns with previous New Zealand investigations.[[2,18]] Transport incidents were the most frequent cause (42.3%), but despite the same ICD-10-AM cause categories, an earlier New Zealand study[[2]] observed transport incidents were involved in only 19.0% of TBI. This discrepancy is likely due to the increased requirement of hospitalisation following transport incidents due to multi-trauma occurring with or without a serious TBI. Indeed, only 21.9% of all hospitalisations in our study were isolated TBI. Notwithstanding, our data are consistent with the earlier study,[[2]] with transport incidents the most common cause of TBI in 15–64-year-olds, falls being particularly important in 0–4- and ≥65-year-olds and interpersonal violence evident in males, Māori and 35–64-year-olds. Cause of injury did not appear to influence severity of TBI, with transport incidents, falls and interpersonal violence similarly represented across mild, moderate and severe TBI-related hospitalisations. Escalating TBI-prevention strategies as they relate to gender, age, ethnicity and cause of injury is warranted. The treatment, management and cultural needs of at-risk population groups must be considered in acute-care and rehabilitation service planning and for work-force availability within hospitals, residential services and in the home and community.

Our study also identifies the complexity and diversity of TBI-related hospitalisations. Although it may seem encouraging that the large proportion (72.1%) of TBI were defined as mild, 75% of this group sustained concomitant injuries that contributed to the requirement for inpatient bed admission and utilisation of hospital resources. Non-isolated injuries were also more common in moderate (87.9%) and severe (78.9%) TBI patients. As the severity of TBI increased, so did mortality, ICU admissions, surgical operations, length of hospital stay and discharge to specialised residential rehabilitation services. In contrast, a study from Israel reported a lower proportion (40.4%) of non-isolated TBI, across all severities, in their national sample of hospitalised patients.[[5]] The disparity is likely explained by differences in the AIS severity cut-off for concomitant injuries to define non-isolated TBI. Notwithstanding, significantly higher rates of mortality, resuscitation, surgery, ICU admission, ICU stay ≥7 days, total hospital stay ≥14 days and residential rehabilitation service requirements were highlighted in non-isolated compared to isolated TBI patients.[[5]] Isolated TBI were also more frequent in females and ≥65-year-olds and more commonly occurred at home, whereas non-isolated TBI occurred more frequently in traffic incidents, particularly among pedestrians and motorcyclists.[[5]] Differences between isolated and non-isolated TBI have important implications for assessment and acute management decisions, resource allocation, collaborative multi-disciplinary teamwork, hospital discharge planning and rehabilitation service provision.

Reporting inter-facility transfers provides a unique insight into the journey of care pathway experienced by patients. The majority (80.5%) of patients remained at the same TMT facility until discharge. It is likely that the 650 (of 1,118) transfers that occurred between the smaller hospitals and Waikato Hospital were due to more severe injuries requiring the resources of the Level 1 Trauma Centre. The 90 patients that had a final discharge destination at a TMT hospital for acute care or convalescence purposes suggests the TR is not currently capturing all patient transfers and discharges. Ongoing development and data collection processes for the TR should ensure patients are completely and accurately tracked through the inpatient acute care and rehabilitation journey. In doing so, assessment of the appropriateness, timeliness, cost and outcome of patient transport between facilities will be possible and serve as a quality control indicator for efficiency in trauma systems,[[19]] and also highlight inequities in health service provision. Such indicators are important given 41.9% of all inter-facility transfers were to designated out-of-region acute care and rehabilitation centres.

The ACC TBI Strategy and Action Plan (2017–2021) suggests TBI services are fragmented and poorly coordinated with support provided in isolation of each other and in isolation to the personal circumstances of people with a TBI.[[6]] Indeed, utilisation and access to rehabilitation services may be significant barriers for people with TBI and delays in service delivery affect rehabilitation progress. In the 12 months after injury, only 32%–37% of Hamilton City and Waikato District residents who sustained mild and moderate/severe TBI reported to follow-up with general practitioners.[[20]] Allied health and specialist medical service provision was also only received by 17% and 14% of the mild TBI cohort, and 41% and 29% of those with moderate-severe TBI, respectively.[[20]] This is concerning given that at 12 months after injury 48% of adults with mild TBI report persistent symptoms.[[21,22]] The sustained and ongoing long-term skills shortage of rehabilitation providers throughout New Zealand,[[23]] discrepancies in the ratio of rehabilitation providers for rural areas and the disproportionately low participation of Māori in the rehabilitation workforce[[24]] may contribute to the low access and utilisation of rehabilitation services. The costly assessment, treatment and rehabilitation of TBI may also be a barrier to progress for affected individuals and health systems. The 2010 financial burden of TBI to New Zealand, including hospitalisations, outpatient rehabilitation, equipment and home modifications and productivity loss for the person affected, was estimated at US$101 million, with projections increasing 20.9% to US$123 million by 2020.[[20]]

A limitation of the study was not utilising the Glasgow Coma Scale (GCS) for comparison with other TBI studies that did use this measure for diagnostic purposes. This decision was made as GCS is not assessed for every TBI patient during the initial hospital admission phase and mechanisms not related to TBI can induce changes in GCS, including psychological stress, drugs and alcohol and concomitant injuries.[[25]] We also reiterate that the nature of this study was not to report incidence but rather the growing volume of TBI-related hospital admissions, which exceeds the rate of population growth, and the impact this has on a regional health system. Acute care hospital costs would also lend further valuable information to this study.

Conclusion

The growing volume and complexity of TBI-related hospitalisations identified in this study have significant implications for affected individuals, their families/whānau and for health system resource planning and allocation. Despite current injury prevention initiatives, males, Māori and 0–4- and 15–34-year-olds are proportionately over-represented in TBI-related hospitalisations. Transport incidents and falls remain key causes of TBI and concomitant injuries. The current requirement for out-of-region transfers for an average 59 TMT residents with TBI each year to acute care and specialised rehabilitation facilities requires service delivery level review and should ideally include qualitative work on patient experiences to optimise care and outcomes.

Summary

Abstract

Aim

To investigate the volume, injury characteristics and journey of Te Manawa Taki/Midland (TMT) residents hospitalised with a traumatic brain injury (TBI).

Method

A retrospective review of TMT Trauma Registry data between 1 January 2012 and 31 December 2019 was conducted. Eligible patients (n=4,875) were TMT residents hospitalised with an injury to the brain parenchyma.

Results

An average 609 residents were hospitalised with a TBI diagnosis per year, increasing by an average of 7.0% annually. Males, Māori and 0–4- and 15–34-year-olds were proportionately over-represented. Transport incidents and falls were key mechanisms. Mild, moderate and severe TBI, derived by Abbreviated Injury Scale severity scores, were classified in 72.1%, 22.6% and 5.3% of patients, respectively. Concomitant injuries occurred in 78.1% of patients. Brain surgery was required by 3.5%, other surgery by 25.5% and intensive care by 14.9%, and 3.7% died. Mean length of hospitalisation was 5.8±9.3 days. There were 1,118 inter-facility transfers: 41.9% to designated out-of-region acute care and rehabilitation centres, an annual average of 59 TMT-domiciled patients.

Conclusion

The increasing volume of diverse TBI hospitalisations represents a major burden on individuals, communities and health services. Effective strategies are needed to prevent injury and ensure treatment and rehabilitation are equitable and patient focused.

Author Information

Maria Bentley: Midland Trauma System, Waikato District Health Board, Hamilton. Pragya Singhal: Midland Trauma System, Waikato District Health Board, Hamilton. Grant Christey: Midland Trauma System, Waikato District Health Board, Hamilton; Waikato Clinical School, University of Auckland; Waikato Hospital Trauma Service. Waikato District Health Board, Hamilton. Janet Amey: Midland Trauma System, Waikato District Health Board, Hamilton.

Acknowledgements

This study required the resources of the Te Manawa Taki/Midland Trauma System to complete. Data acquisition was undertaken by clinical and administrative staff in each respective Trauma Service in the Lakes, Tairawhiti, Taranaki, Bay of Plenty and Waikato district health boards. Contributions from the Hub staff included data coding, entry, quality checking and trauma registry management.

Correspondence

Grant Christey: Midland Trauma System, Waikato District Health Board, Hamilton; Waikato Clinical School, University of Auckland; Waikato Hospital Trauma Service. Waikato District Health Board, Hamilton

Correspondence Email

grant.christey@waikatodhb.health.nz

Competing Interests

Nil.

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7) Theadom A, Starkey N, Barker-Collo S, Jones K, et al on behalf of the Bionic Research Group. Population-based cohort study of the impacts of mild traumatic brain injury in adults four years post-injury. PLoS One. 2018;13(1): e0191655. doi:10.1371/journal.pone.0191655.

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Globally, traumatic brain injury (TBI) is the foremost cause of death and disability in both children and young adults.[[1,2]] New Zealand is no exception, with an incidence rate in 2010–2011 of 790/100,000 observed in Hamilton City and Waikato District.[[2]] At this time, TBI was more prevalent in males, 0–34-year-olds, Māori and those living in rural areas, with falls, exposure to mechanical forces, transport incidents and interpersonal violence recognised as important causes.[[2]]

Traumatic brain injuries are significant in number, diverse in nature with a severity range from mild concussion and moderate brain oedema, haematoma and/or haemorrhage, to severe crush or penetrating injury causing extended loss of consciousness.[[3,4]] TBI also commonly occur with other concomitant injuries requiring additional assessment, treatment and rehabilitation.[[3,4]] Accordingly, TBI can temporarily or permanently affect cognitive, behavioural, emotional and physical aspects of quality of life, including the ability to live independently, maintain relationships and return to work, education or leisure activities.[[6–8]] Early, equitable and coordinated management is therefore essential to optimise outcomes.

Although the incidence, at-risk populations and common causes of TBI were identified in New Zealand a decade ago[[2]], less is known about the patient journey through the TMT hospital setting of patients who are admitted with a diagnosis that includes TBI. The TMT Trauma Registry (TR) contains data to enable evaluation of demographics, injury complexity, utilisation of hospital resources and discharge destinations for individuals admitted to acute care facilities in the region. Such information assists quantification of the burden of hospitalised TBI on affected individuals, their families/whānau and regional health systems. It will also assist identification of issues pertaining to clinical service provision and rehabilitation pathways. Anecdotal evidence pointed to an increasing volume of TBI related injury across the region.

The aim of this study is to investigate not only the volume and demographic features of patients, but also processes of care, injury events, injury types and treatment and resource allocation of TMT residents hospitalised with a TBI.

The TMT region encompasses five district health boards (DHB) and displays demographic characteristics reflective of New Zealand for median age (35 vs 38 years) and gender (48% male) and a higher proportion of Māori (26.5% vs 15.7%).[[9]] The average regional population during the study period was 909,109, with an average annual population increase of 2.0%. Providing tertiary care to the region Waikato Hospital is a Royal Australasian College of Surgeons verified Level 1 Trauma Centre,[[10]] with specialist teams and resources to manage all acute major and non-major trauma. TBI rehabilitation options in the region include non-specific inpatient wards and DHB and Accident Compensation Corporation (ACC) contracts in the outpatient, community and home-based settings.

Methods

A retrospective review of the TR was conducted from 1 January 2012 to 31 December 2019. The TR collects comprehensive data on all trauma patients across the region admitted to hospital, within seven days of injury. All patients with TBI were defined and identified by use of the 137 Abbreviated Injury Scale (AIS)[[3]] codes from body region 1 (cranium and brain) defining injury to and around the brain parenchyma. Exclusions included injuries to cranial and spinal nerves, vascular structures and bone in the absence of brain parenchymal disruption. Consistent with other trauma registries, exclusions included insufficiency or peri-prosthetic fractures, exertional injuries, hanging, near drowning or asphyxiation and injuries that occur as a result of a pre-existing medical condition.

Severity of TBI was determined by AIS score, ranging from 1 (minor, 0% threat to life) through to 6 (maximum, 100% threat to life). In accordance with recommendations[[10]] and other trauma registry studies,[[12–14]] TBI was defined as mild, moderate or severe by AIS severity scores of 1–2, 3–4 and ≥5, respectively. Isolated TBI were defined when no other anatomic region had an AIS score. The Injury Severity Scale (ISS)[[15]] standardises injuries sustained in a single incident with thresholds set at ISS≥13 for major and ISS≤12 for non-major.[[16]] ISS scores are calculated from the square of the highest AIS scores from a maximum of three body systems. We determined the contribution of TBI to ISS scores as a proportion (%) to provide an indication of the severity of TBI to multi-trauma patients.

Hospital resource allocation characteristics including surgical procedures and admission to intensive care were categorically coded. Surgical procedures that have a direct impact on brain parenchyma were identified by International Classification of Disease (ICD-10-AM)[[17]] codes (n=34). Length of hospital stay was calculated as mean (SD) and median (IQR). In addition to final discharge destinations from TMT hospitals, all transfers to out-of-region facilities during each patient’s journey were also recorded.

Populations were estimated from Stats NZ census data.[[9]] Ethnicities were categorised as Māori, European and Other according to Stats NZ classifications. Mechanism of injury was classified by the ICD-10-AM[[17]] and grouped by unintentional falls, transport incidents (traffic and non-traffic related), interpersonal violence, exposure to external forces and other causes. Descriptive analyses were performed in Excel (Microsoft Office Professional Plus 2016) and data are presented as number (%), except when outlined as mean (SD) and median (IQR). Ethical approval was deemed out of scope by the New Zealand Health and Disability Ethics Committee and project approval was provided following locality assessment by Waikato DHB and the Māori Research Review Committee (RD21026).

Results

Across the eight-year study period, 4,875 TMT residents were hospitalised with a diagnosis that included TBI, with an average of 609 per year. Figure 1 highlights the increasing trend (R[[2]]=0.833) with an average annual increase of 7.0% and 248 (152%) more TBI-related hospitalisations in 2019 compared to 2012. A further 490 non-domiciled patients were also hospitalised at a TMT facility for an injury that included a diagnosis of TBI but are excluded from analyses.

Figure 1: Count of hospitalisations that included a traumatic brain injury diagnosis by year in Te Manawa Taki residents.

TBI-related hospitalisations were dominated by males (66.4%), Europeans (61.3%) and by age groups 15–34 (30.7%) and 35–64 (25.3%). However, as a percentage of the respective sub-populations, Māori had 33.4% more TBI-related hospitalisations than Europeans, and age groups 0–4 (211%) and 15–34 (184%) had more TBI-related hospitalisations than 35–64-year-olds. Transport incidents and falls were the causes for 79.2% of all TBI-related hospitalisations. Falls were particularly important in those aged 0–4 and ≥65. Interpersonal violence was a notable mechanism in males, Māori and 35–64-year-olds. Severity of TBI did not appear to be influenced by the cause of injury, with transport incidents, falls and interpersonal violence similarly represented across all grades of severity in TBI-related hospitalisations (Table 1).

The majority (72.1%) of TBI diagnoses were classified mild by AIS severity score. Of these, 25.0% were isolated TBI, 10.9% had major ISS scores, 6.4% were admitted to intensive care units (ICU) and 22.2% received surgery. Of the sample, 22.6% of TBI diagnoses were classified as moderate and 12.1% had an isolated TBI, 60.2% had major ISS scores, 32.3% were admitted to ICU, 7.2% required brain surgery, 32.3% received other surgical intervention and 6.5% died as a result of their injuries. Of the remaining 260 patients (32.5 per year) classified with severe TBI, 21.2% were isolated TBI, all had major ISS scores, 56.2% were admitted to ICU, 33.5% required brain surgery, 41.9% received other surgical interventions and 35.0% died. The mean and median percent contribution of the TBI diagnosis to the total ISS score was greater than 50% across the whole sample and within each severity group, although wide variation existed. Wide variability in mean and median length of hospital stay was also evident for the total sample and across each severity group. In those who survived, 1.6% of mild, 18.6% of moderate and 43.8% of severe TBI patients travelled to out-of-region specialised services for brain and/or spinal rehabilitation (Table 2). Non-availability of a rehabilitation facility bed was cited as an impediment to timely hospital discharge for 19 patients, with delays ranging from 1–17 days. This is considered an under-estimation as the impediment to discharge variable is not always recorded in the TR.

Inter-facility transfers occurred on 1,118 occasions across the 4,875 patients (Table 3). This number excludes initial admissions to non-TMT facilities where incidents occurred to residents outside of the TMT region and is possibly further under-estimated by the inability of the TR to capture direct transfers from out-of-region acute care facilities to out-of-region rehabilitation facilities. Of the recorded inter-facility transfers, 801 (16.4%) patients were transferred once, 142 (2.9%) twice, eight (0.2%) three times and two ≥4 times to receive necessary care. Transfers commonly occurred between the smaller regional hospitals and Waikato Hospital, the Level 1 Trauma Centre. However, 41.9% (468/1,118) of all inter-facility transfers were to designated out-of-region acute care and rehabilitation centres, equating to an average of 48 adults and 11 children per year. Of the 4,694 patients who survived, home was the most common discharge destination (82.1%) captured by the TR. The remainder were discharged to regional hospitals for rehabilitation (3.6%) or continuing and convalescence care (1.9%), aged care or nursing home not usual residence (2.0%) and out-of-region facilities (8.0%). A further 1.5% left against medical advice.

Table 1: Number of hospitalised traumatic brain injuries by mechanism of injury and demographics in Te Manawa Taki residents (2012–2019). View Table 1.

Table 2: Hospitalisation and health service characteristics by severity of traumatic brain injury in Te Manawa Taki residents (2012–2019). View Table 2.

Table 3: Journey of care pathway of Te Manawa Taki residents hospitalised with a traumatic brain injury (2012–2019). View Table 3.

Discussion

This study provides comprehensive information on domiciled residents in the TMT region who were admitted to hospital with a diagnosis that included TBI. The 7.0% average annual increase in TBI-related hospitalisations, which is higher than the 2.0% average annual population growth, is a major concern for funding, budgeting and resource allocation. The 152% increase in TBI-related hospitalisations between 2012 and 2019 also indicates a rising incidence despite currently established TBI prevention initiatives.[[6]]

In 2010–2011, a prospective TBI investigation of domiciled Hamilton City and Waikato District residents was conducted.[[2]] During the 12-month study, 882 patients with TBI were admitted to Waikato Hospital. This figure is higher than our observations of 479–765 TBI-related hospitalisations per year from the TMT region, and definition differences explain this discrepancy. We defined hospitalisation by admission to an inpatient bed and by death that occurred in the emergency department, whereas the earlier study[[2]] referred to site of case detection by the study team (hospital, family doctor or other), meaning emergency department presentations with or without subsequent admission to an inpatient bed were included. Further, we diagnosed TBI by the AIS which uses radiological and surgical findings to determine anatomical injury to the brain. Conversely, the earlier study[[2]] functionally defined TBI by the presence of confusion or disorientation and/or loss of consciousness and/or post-traumatic amnesia and/or other neurological abnormalities. Nevertheless, regardless of the requirement for hospital admission, the increasing volume of TBI we observed suggests the burden on regional residents and the health system is increasing.

The higher population-based percentage of hospitalisations for males, Māori and those aged 0–4- and 15–34-years-old aligns with previous New Zealand investigations.[[2,18]] Transport incidents were the most frequent cause (42.3%), but despite the same ICD-10-AM cause categories, an earlier New Zealand study[[2]] observed transport incidents were involved in only 19.0% of TBI. This discrepancy is likely due to the increased requirement of hospitalisation following transport incidents due to multi-trauma occurring with or without a serious TBI. Indeed, only 21.9% of all hospitalisations in our study were isolated TBI. Notwithstanding, our data are consistent with the earlier study,[[2]] with transport incidents the most common cause of TBI in 15–64-year-olds, falls being particularly important in 0–4- and ≥65-year-olds and interpersonal violence evident in males, Māori and 35–64-year-olds. Cause of injury did not appear to influence severity of TBI, with transport incidents, falls and interpersonal violence similarly represented across mild, moderate and severe TBI-related hospitalisations. Escalating TBI-prevention strategies as they relate to gender, age, ethnicity and cause of injury is warranted. The treatment, management and cultural needs of at-risk population groups must be considered in acute-care and rehabilitation service planning and for work-force availability within hospitals, residential services and in the home and community.

Our study also identifies the complexity and diversity of TBI-related hospitalisations. Although it may seem encouraging that the large proportion (72.1%) of TBI were defined as mild, 75% of this group sustained concomitant injuries that contributed to the requirement for inpatient bed admission and utilisation of hospital resources. Non-isolated injuries were also more common in moderate (87.9%) and severe (78.9%) TBI patients. As the severity of TBI increased, so did mortality, ICU admissions, surgical operations, length of hospital stay and discharge to specialised residential rehabilitation services. In contrast, a study from Israel reported a lower proportion (40.4%) of non-isolated TBI, across all severities, in their national sample of hospitalised patients.[[5]] The disparity is likely explained by differences in the AIS severity cut-off for concomitant injuries to define non-isolated TBI. Notwithstanding, significantly higher rates of mortality, resuscitation, surgery, ICU admission, ICU stay ≥7 days, total hospital stay ≥14 days and residential rehabilitation service requirements were highlighted in non-isolated compared to isolated TBI patients.[[5]] Isolated TBI were also more frequent in females and ≥65-year-olds and more commonly occurred at home, whereas non-isolated TBI occurred more frequently in traffic incidents, particularly among pedestrians and motorcyclists.[[5]] Differences between isolated and non-isolated TBI have important implications for assessment and acute management decisions, resource allocation, collaborative multi-disciplinary teamwork, hospital discharge planning and rehabilitation service provision.

Reporting inter-facility transfers provides a unique insight into the journey of care pathway experienced by patients. The majority (80.5%) of patients remained at the same TMT facility until discharge. It is likely that the 650 (of 1,118) transfers that occurred between the smaller hospitals and Waikato Hospital were due to more severe injuries requiring the resources of the Level 1 Trauma Centre. The 90 patients that had a final discharge destination at a TMT hospital for acute care or convalescence purposes suggests the TR is not currently capturing all patient transfers and discharges. Ongoing development and data collection processes for the TR should ensure patients are completely and accurately tracked through the inpatient acute care and rehabilitation journey. In doing so, assessment of the appropriateness, timeliness, cost and outcome of patient transport between facilities will be possible and serve as a quality control indicator for efficiency in trauma systems,[[19]] and also highlight inequities in health service provision. Such indicators are important given 41.9% of all inter-facility transfers were to designated out-of-region acute care and rehabilitation centres.

The ACC TBI Strategy and Action Plan (2017–2021) suggests TBI services are fragmented and poorly coordinated with support provided in isolation of each other and in isolation to the personal circumstances of people with a TBI.[[6]] Indeed, utilisation and access to rehabilitation services may be significant barriers for people with TBI and delays in service delivery affect rehabilitation progress. In the 12 months after injury, only 32%–37% of Hamilton City and Waikato District residents who sustained mild and moderate/severe TBI reported to follow-up with general practitioners.[[20]] Allied health and specialist medical service provision was also only received by 17% and 14% of the mild TBI cohort, and 41% and 29% of those with moderate-severe TBI, respectively.[[20]] This is concerning given that at 12 months after injury 48% of adults with mild TBI report persistent symptoms.[[21,22]] The sustained and ongoing long-term skills shortage of rehabilitation providers throughout New Zealand,[[23]] discrepancies in the ratio of rehabilitation providers for rural areas and the disproportionately low participation of Māori in the rehabilitation workforce[[24]] may contribute to the low access and utilisation of rehabilitation services. The costly assessment, treatment and rehabilitation of TBI may also be a barrier to progress for affected individuals and health systems. The 2010 financial burden of TBI to New Zealand, including hospitalisations, outpatient rehabilitation, equipment and home modifications and productivity loss for the person affected, was estimated at US$101 million, with projections increasing 20.9% to US$123 million by 2020.[[20]]

A limitation of the study was not utilising the Glasgow Coma Scale (GCS) for comparison with other TBI studies that did use this measure for diagnostic purposes. This decision was made as GCS is not assessed for every TBI patient during the initial hospital admission phase and mechanisms not related to TBI can induce changes in GCS, including psychological stress, drugs and alcohol and concomitant injuries.[[25]] We also reiterate that the nature of this study was not to report incidence but rather the growing volume of TBI-related hospital admissions, which exceeds the rate of population growth, and the impact this has on a regional health system. Acute care hospital costs would also lend further valuable information to this study.

Conclusion

The growing volume and complexity of TBI-related hospitalisations identified in this study have significant implications for affected individuals, their families/whānau and for health system resource planning and allocation. Despite current injury prevention initiatives, males, Māori and 0–4- and 15–34-year-olds are proportionately over-represented in TBI-related hospitalisations. Transport incidents and falls remain key causes of TBI and concomitant injuries. The current requirement for out-of-region transfers for an average 59 TMT residents with TBI each year to acute care and specialised rehabilitation facilities requires service delivery level review and should ideally include qualitative work on patient experiences to optimise care and outcomes.

Summary

Abstract

Aim

To investigate the volume, injury characteristics and journey of Te Manawa Taki/Midland (TMT) residents hospitalised with a traumatic brain injury (TBI).

Method

A retrospective review of TMT Trauma Registry data between 1 January 2012 and 31 December 2019 was conducted. Eligible patients (n=4,875) were TMT residents hospitalised with an injury to the brain parenchyma.

Results

An average 609 residents were hospitalised with a TBI diagnosis per year, increasing by an average of 7.0% annually. Males, Māori and 0–4- and 15–34-year-olds were proportionately over-represented. Transport incidents and falls were key mechanisms. Mild, moderate and severe TBI, derived by Abbreviated Injury Scale severity scores, were classified in 72.1%, 22.6% and 5.3% of patients, respectively. Concomitant injuries occurred in 78.1% of patients. Brain surgery was required by 3.5%, other surgery by 25.5% and intensive care by 14.9%, and 3.7% died. Mean length of hospitalisation was 5.8±9.3 days. There were 1,118 inter-facility transfers: 41.9% to designated out-of-region acute care and rehabilitation centres, an annual average of 59 TMT-domiciled patients.

Conclusion

The increasing volume of diverse TBI hospitalisations represents a major burden on individuals, communities and health services. Effective strategies are needed to prevent injury and ensure treatment and rehabilitation are equitable and patient focused.

Author Information

Maria Bentley: Midland Trauma System, Waikato District Health Board, Hamilton. Pragya Singhal: Midland Trauma System, Waikato District Health Board, Hamilton. Grant Christey: Midland Trauma System, Waikato District Health Board, Hamilton; Waikato Clinical School, University of Auckland; Waikato Hospital Trauma Service. Waikato District Health Board, Hamilton. Janet Amey: Midland Trauma System, Waikato District Health Board, Hamilton.

Acknowledgements

This study required the resources of the Te Manawa Taki/Midland Trauma System to complete. Data acquisition was undertaken by clinical and administrative staff in each respective Trauma Service in the Lakes, Tairawhiti, Taranaki, Bay of Plenty and Waikato district health boards. Contributions from the Hub staff included data coding, entry, quality checking and trauma registry management.

Correspondence

Grant Christey: Midland Trauma System, Waikato District Health Board, Hamilton; Waikato Clinical School, University of Auckland; Waikato Hospital Trauma Service. Waikato District Health Board, Hamilton

Correspondence Email

grant.christey@waikatodhb.health.nz

Competing Interests

Nil.

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Globally, traumatic brain injury (TBI) is the foremost cause of death and disability in both children and young adults.[[1,2]] New Zealand is no exception, with an incidence rate in 2010–2011 of 790/100,000 observed in Hamilton City and Waikato District.[[2]] At this time, TBI was more prevalent in males, 0–34-year-olds, Māori and those living in rural areas, with falls, exposure to mechanical forces, transport incidents and interpersonal violence recognised as important causes.[[2]]

Traumatic brain injuries are significant in number, diverse in nature with a severity range from mild concussion and moderate brain oedema, haematoma and/or haemorrhage, to severe crush or penetrating injury causing extended loss of consciousness.[[3,4]] TBI also commonly occur with other concomitant injuries requiring additional assessment, treatment and rehabilitation.[[3,4]] Accordingly, TBI can temporarily or permanently affect cognitive, behavioural, emotional and physical aspects of quality of life, including the ability to live independently, maintain relationships and return to work, education or leisure activities.[[6–8]] Early, equitable and coordinated management is therefore essential to optimise outcomes.

Although the incidence, at-risk populations and common causes of TBI were identified in New Zealand a decade ago[[2]], less is known about the patient journey through the TMT hospital setting of patients who are admitted with a diagnosis that includes TBI. The TMT Trauma Registry (TR) contains data to enable evaluation of demographics, injury complexity, utilisation of hospital resources and discharge destinations for individuals admitted to acute care facilities in the region. Such information assists quantification of the burden of hospitalised TBI on affected individuals, their families/whānau and regional health systems. It will also assist identification of issues pertaining to clinical service provision and rehabilitation pathways. Anecdotal evidence pointed to an increasing volume of TBI related injury across the region.

The aim of this study is to investigate not only the volume and demographic features of patients, but also processes of care, injury events, injury types and treatment and resource allocation of TMT residents hospitalised with a TBI.

The TMT region encompasses five district health boards (DHB) and displays demographic characteristics reflective of New Zealand for median age (35 vs 38 years) and gender (48% male) and a higher proportion of Māori (26.5% vs 15.7%).[[9]] The average regional population during the study period was 909,109, with an average annual population increase of 2.0%. Providing tertiary care to the region Waikato Hospital is a Royal Australasian College of Surgeons verified Level 1 Trauma Centre,[[10]] with specialist teams and resources to manage all acute major and non-major trauma. TBI rehabilitation options in the region include non-specific inpatient wards and DHB and Accident Compensation Corporation (ACC) contracts in the outpatient, community and home-based settings.

Methods

A retrospective review of the TR was conducted from 1 January 2012 to 31 December 2019. The TR collects comprehensive data on all trauma patients across the region admitted to hospital, within seven days of injury. All patients with TBI were defined and identified by use of the 137 Abbreviated Injury Scale (AIS)[[3]] codes from body region 1 (cranium and brain) defining injury to and around the brain parenchyma. Exclusions included injuries to cranial and spinal nerves, vascular structures and bone in the absence of brain parenchymal disruption. Consistent with other trauma registries, exclusions included insufficiency or peri-prosthetic fractures, exertional injuries, hanging, near drowning or asphyxiation and injuries that occur as a result of a pre-existing medical condition.

Severity of TBI was determined by AIS score, ranging from 1 (minor, 0% threat to life) through to 6 (maximum, 100% threat to life). In accordance with recommendations[[10]] and other trauma registry studies,[[12–14]] TBI was defined as mild, moderate or severe by AIS severity scores of 1–2, 3–4 and ≥5, respectively. Isolated TBI were defined when no other anatomic region had an AIS score. The Injury Severity Scale (ISS)[[15]] standardises injuries sustained in a single incident with thresholds set at ISS≥13 for major and ISS≤12 for non-major.[[16]] ISS scores are calculated from the square of the highest AIS scores from a maximum of three body systems. We determined the contribution of TBI to ISS scores as a proportion (%) to provide an indication of the severity of TBI to multi-trauma patients.

Hospital resource allocation characteristics including surgical procedures and admission to intensive care were categorically coded. Surgical procedures that have a direct impact on brain parenchyma were identified by International Classification of Disease (ICD-10-AM)[[17]] codes (n=34). Length of hospital stay was calculated as mean (SD) and median (IQR). In addition to final discharge destinations from TMT hospitals, all transfers to out-of-region facilities during each patient’s journey were also recorded.

Populations were estimated from Stats NZ census data.[[9]] Ethnicities were categorised as Māori, European and Other according to Stats NZ classifications. Mechanism of injury was classified by the ICD-10-AM[[17]] and grouped by unintentional falls, transport incidents (traffic and non-traffic related), interpersonal violence, exposure to external forces and other causes. Descriptive analyses were performed in Excel (Microsoft Office Professional Plus 2016) and data are presented as number (%), except when outlined as mean (SD) and median (IQR). Ethical approval was deemed out of scope by the New Zealand Health and Disability Ethics Committee and project approval was provided following locality assessment by Waikato DHB and the Māori Research Review Committee (RD21026).

Results

Across the eight-year study period, 4,875 TMT residents were hospitalised with a diagnosis that included TBI, with an average of 609 per year. Figure 1 highlights the increasing trend (R[[2]]=0.833) with an average annual increase of 7.0% and 248 (152%) more TBI-related hospitalisations in 2019 compared to 2012. A further 490 non-domiciled patients were also hospitalised at a TMT facility for an injury that included a diagnosis of TBI but are excluded from analyses.

Figure 1: Count of hospitalisations that included a traumatic brain injury diagnosis by year in Te Manawa Taki residents.

TBI-related hospitalisations were dominated by males (66.4%), Europeans (61.3%) and by age groups 15–34 (30.7%) and 35–64 (25.3%). However, as a percentage of the respective sub-populations, Māori had 33.4% more TBI-related hospitalisations than Europeans, and age groups 0–4 (211%) and 15–34 (184%) had more TBI-related hospitalisations than 35–64-year-olds. Transport incidents and falls were the causes for 79.2% of all TBI-related hospitalisations. Falls were particularly important in those aged 0–4 and ≥65. Interpersonal violence was a notable mechanism in males, Māori and 35–64-year-olds. Severity of TBI did not appear to be influenced by the cause of injury, with transport incidents, falls and interpersonal violence similarly represented across all grades of severity in TBI-related hospitalisations (Table 1).

The majority (72.1%) of TBI diagnoses were classified mild by AIS severity score. Of these, 25.0% were isolated TBI, 10.9% had major ISS scores, 6.4% were admitted to intensive care units (ICU) and 22.2% received surgery. Of the sample, 22.6% of TBI diagnoses were classified as moderate and 12.1% had an isolated TBI, 60.2% had major ISS scores, 32.3% were admitted to ICU, 7.2% required brain surgery, 32.3% received other surgical intervention and 6.5% died as a result of their injuries. Of the remaining 260 patients (32.5 per year) classified with severe TBI, 21.2% were isolated TBI, all had major ISS scores, 56.2% were admitted to ICU, 33.5% required brain surgery, 41.9% received other surgical interventions and 35.0% died. The mean and median percent contribution of the TBI diagnosis to the total ISS score was greater than 50% across the whole sample and within each severity group, although wide variation existed. Wide variability in mean and median length of hospital stay was also evident for the total sample and across each severity group. In those who survived, 1.6% of mild, 18.6% of moderate and 43.8% of severe TBI patients travelled to out-of-region specialised services for brain and/or spinal rehabilitation (Table 2). Non-availability of a rehabilitation facility bed was cited as an impediment to timely hospital discharge for 19 patients, with delays ranging from 1–17 days. This is considered an under-estimation as the impediment to discharge variable is not always recorded in the TR.

Inter-facility transfers occurred on 1,118 occasions across the 4,875 patients (Table 3). This number excludes initial admissions to non-TMT facilities where incidents occurred to residents outside of the TMT region and is possibly further under-estimated by the inability of the TR to capture direct transfers from out-of-region acute care facilities to out-of-region rehabilitation facilities. Of the recorded inter-facility transfers, 801 (16.4%) patients were transferred once, 142 (2.9%) twice, eight (0.2%) three times and two ≥4 times to receive necessary care. Transfers commonly occurred between the smaller regional hospitals and Waikato Hospital, the Level 1 Trauma Centre. However, 41.9% (468/1,118) of all inter-facility transfers were to designated out-of-region acute care and rehabilitation centres, equating to an average of 48 adults and 11 children per year. Of the 4,694 patients who survived, home was the most common discharge destination (82.1%) captured by the TR. The remainder were discharged to regional hospitals for rehabilitation (3.6%) or continuing and convalescence care (1.9%), aged care or nursing home not usual residence (2.0%) and out-of-region facilities (8.0%). A further 1.5% left against medical advice.

Table 1: Number of hospitalised traumatic brain injuries by mechanism of injury and demographics in Te Manawa Taki residents (2012–2019). View Table 1.

Table 2: Hospitalisation and health service characteristics by severity of traumatic brain injury in Te Manawa Taki residents (2012–2019). View Table 2.

Table 3: Journey of care pathway of Te Manawa Taki residents hospitalised with a traumatic brain injury (2012–2019). View Table 3.

Discussion

This study provides comprehensive information on domiciled residents in the TMT region who were admitted to hospital with a diagnosis that included TBI. The 7.0% average annual increase in TBI-related hospitalisations, which is higher than the 2.0% average annual population growth, is a major concern for funding, budgeting and resource allocation. The 152% increase in TBI-related hospitalisations between 2012 and 2019 also indicates a rising incidence despite currently established TBI prevention initiatives.[[6]]

In 2010–2011, a prospective TBI investigation of domiciled Hamilton City and Waikato District residents was conducted.[[2]] During the 12-month study, 882 patients with TBI were admitted to Waikato Hospital. This figure is higher than our observations of 479–765 TBI-related hospitalisations per year from the TMT region, and definition differences explain this discrepancy. We defined hospitalisation by admission to an inpatient bed and by death that occurred in the emergency department, whereas the earlier study[[2]] referred to site of case detection by the study team (hospital, family doctor or other), meaning emergency department presentations with or without subsequent admission to an inpatient bed were included. Further, we diagnosed TBI by the AIS which uses radiological and surgical findings to determine anatomical injury to the brain. Conversely, the earlier study[[2]] functionally defined TBI by the presence of confusion or disorientation and/or loss of consciousness and/or post-traumatic amnesia and/or other neurological abnormalities. Nevertheless, regardless of the requirement for hospital admission, the increasing volume of TBI we observed suggests the burden on regional residents and the health system is increasing.

The higher population-based percentage of hospitalisations for males, Māori and those aged 0–4- and 15–34-years-old aligns with previous New Zealand investigations.[[2,18]] Transport incidents were the most frequent cause (42.3%), but despite the same ICD-10-AM cause categories, an earlier New Zealand study[[2]] observed transport incidents were involved in only 19.0% of TBI. This discrepancy is likely due to the increased requirement of hospitalisation following transport incidents due to multi-trauma occurring with or without a serious TBI. Indeed, only 21.9% of all hospitalisations in our study were isolated TBI. Notwithstanding, our data are consistent with the earlier study,[[2]] with transport incidents the most common cause of TBI in 15–64-year-olds, falls being particularly important in 0–4- and ≥65-year-olds and interpersonal violence evident in males, Māori and 35–64-year-olds. Cause of injury did not appear to influence severity of TBI, with transport incidents, falls and interpersonal violence similarly represented across mild, moderate and severe TBI-related hospitalisations. Escalating TBI-prevention strategies as they relate to gender, age, ethnicity and cause of injury is warranted. The treatment, management and cultural needs of at-risk population groups must be considered in acute-care and rehabilitation service planning and for work-force availability within hospitals, residential services and in the home and community.

Our study also identifies the complexity and diversity of TBI-related hospitalisations. Although it may seem encouraging that the large proportion (72.1%) of TBI were defined as mild, 75% of this group sustained concomitant injuries that contributed to the requirement for inpatient bed admission and utilisation of hospital resources. Non-isolated injuries were also more common in moderate (87.9%) and severe (78.9%) TBI patients. As the severity of TBI increased, so did mortality, ICU admissions, surgical operations, length of hospital stay and discharge to specialised residential rehabilitation services. In contrast, a study from Israel reported a lower proportion (40.4%) of non-isolated TBI, across all severities, in their national sample of hospitalised patients.[[5]] The disparity is likely explained by differences in the AIS severity cut-off for concomitant injuries to define non-isolated TBI. Notwithstanding, significantly higher rates of mortality, resuscitation, surgery, ICU admission, ICU stay ≥7 days, total hospital stay ≥14 days and residential rehabilitation service requirements were highlighted in non-isolated compared to isolated TBI patients.[[5]] Isolated TBI were also more frequent in females and ≥65-year-olds and more commonly occurred at home, whereas non-isolated TBI occurred more frequently in traffic incidents, particularly among pedestrians and motorcyclists.[[5]] Differences between isolated and non-isolated TBI have important implications for assessment and acute management decisions, resource allocation, collaborative multi-disciplinary teamwork, hospital discharge planning and rehabilitation service provision.

Reporting inter-facility transfers provides a unique insight into the journey of care pathway experienced by patients. The majority (80.5%) of patients remained at the same TMT facility until discharge. It is likely that the 650 (of 1,118) transfers that occurred between the smaller hospitals and Waikato Hospital were due to more severe injuries requiring the resources of the Level 1 Trauma Centre. The 90 patients that had a final discharge destination at a TMT hospital for acute care or convalescence purposes suggests the TR is not currently capturing all patient transfers and discharges. Ongoing development and data collection processes for the TR should ensure patients are completely and accurately tracked through the inpatient acute care and rehabilitation journey. In doing so, assessment of the appropriateness, timeliness, cost and outcome of patient transport between facilities will be possible and serve as a quality control indicator for efficiency in trauma systems,[[19]] and also highlight inequities in health service provision. Such indicators are important given 41.9% of all inter-facility transfers were to designated out-of-region acute care and rehabilitation centres.

The ACC TBI Strategy and Action Plan (2017–2021) suggests TBI services are fragmented and poorly coordinated with support provided in isolation of each other and in isolation to the personal circumstances of people with a TBI.[[6]] Indeed, utilisation and access to rehabilitation services may be significant barriers for people with TBI and delays in service delivery affect rehabilitation progress. In the 12 months after injury, only 32%–37% of Hamilton City and Waikato District residents who sustained mild and moderate/severe TBI reported to follow-up with general practitioners.[[20]] Allied health and specialist medical service provision was also only received by 17% and 14% of the mild TBI cohort, and 41% and 29% of those with moderate-severe TBI, respectively.[[20]] This is concerning given that at 12 months after injury 48% of adults with mild TBI report persistent symptoms.[[21,22]] The sustained and ongoing long-term skills shortage of rehabilitation providers throughout New Zealand,[[23]] discrepancies in the ratio of rehabilitation providers for rural areas and the disproportionately low participation of Māori in the rehabilitation workforce[[24]] may contribute to the low access and utilisation of rehabilitation services. The costly assessment, treatment and rehabilitation of TBI may also be a barrier to progress for affected individuals and health systems. The 2010 financial burden of TBI to New Zealand, including hospitalisations, outpatient rehabilitation, equipment and home modifications and productivity loss for the person affected, was estimated at US$101 million, with projections increasing 20.9% to US$123 million by 2020.[[20]]

A limitation of the study was not utilising the Glasgow Coma Scale (GCS) for comparison with other TBI studies that did use this measure for diagnostic purposes. This decision was made as GCS is not assessed for every TBI patient during the initial hospital admission phase and mechanisms not related to TBI can induce changes in GCS, including psychological stress, drugs and alcohol and concomitant injuries.[[25]] We also reiterate that the nature of this study was not to report incidence but rather the growing volume of TBI-related hospital admissions, which exceeds the rate of population growth, and the impact this has on a regional health system. Acute care hospital costs would also lend further valuable information to this study.

Conclusion

The growing volume and complexity of TBI-related hospitalisations identified in this study have significant implications for affected individuals, their families/whānau and for health system resource planning and allocation. Despite current injury prevention initiatives, males, Māori and 0–4- and 15–34-year-olds are proportionately over-represented in TBI-related hospitalisations. Transport incidents and falls remain key causes of TBI and concomitant injuries. The current requirement for out-of-region transfers for an average 59 TMT residents with TBI each year to acute care and specialised rehabilitation facilities requires service delivery level review and should ideally include qualitative work on patient experiences to optimise care and outcomes.

Summary

Abstract

Aim

To investigate the volume, injury characteristics and journey of Te Manawa Taki/Midland (TMT) residents hospitalised with a traumatic brain injury (TBI).

Method

A retrospective review of TMT Trauma Registry data between 1 January 2012 and 31 December 2019 was conducted. Eligible patients (n=4,875) were TMT residents hospitalised with an injury to the brain parenchyma.

Results

An average 609 residents were hospitalised with a TBI diagnosis per year, increasing by an average of 7.0% annually. Males, Māori and 0–4- and 15–34-year-olds were proportionately over-represented. Transport incidents and falls were key mechanisms. Mild, moderate and severe TBI, derived by Abbreviated Injury Scale severity scores, were classified in 72.1%, 22.6% and 5.3% of patients, respectively. Concomitant injuries occurred in 78.1% of patients. Brain surgery was required by 3.5%, other surgery by 25.5% and intensive care by 14.9%, and 3.7% died. Mean length of hospitalisation was 5.8±9.3 days. There were 1,118 inter-facility transfers: 41.9% to designated out-of-region acute care and rehabilitation centres, an annual average of 59 TMT-domiciled patients.

Conclusion

The increasing volume of diverse TBI hospitalisations represents a major burden on individuals, communities and health services. Effective strategies are needed to prevent injury and ensure treatment and rehabilitation are equitable and patient focused.

Author Information

Maria Bentley: Midland Trauma System, Waikato District Health Board, Hamilton. Pragya Singhal: Midland Trauma System, Waikato District Health Board, Hamilton. Grant Christey: Midland Trauma System, Waikato District Health Board, Hamilton; Waikato Clinical School, University of Auckland; Waikato Hospital Trauma Service. Waikato District Health Board, Hamilton. Janet Amey: Midland Trauma System, Waikato District Health Board, Hamilton.

Acknowledgements

This study required the resources of the Te Manawa Taki/Midland Trauma System to complete. Data acquisition was undertaken by clinical and administrative staff in each respective Trauma Service in the Lakes, Tairawhiti, Taranaki, Bay of Plenty and Waikato district health boards. Contributions from the Hub staff included data coding, entry, quality checking and trauma registry management.

Correspondence

Grant Christey: Midland Trauma System, Waikato District Health Board, Hamilton; Waikato Clinical School, University of Auckland; Waikato Hospital Trauma Service. Waikato District Health Board, Hamilton

Correspondence Email

grant.christey@waikatodhb.health.nz

Competing Interests

Nil.

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