Smartphone use for Paediatric Calculations in Emergencies (SPaCE).

BACKGROUND: The preparation for critically ill children involves calculating drug and fluid volumes using the commonly taught WETFLAG (weight, energy, endotracheal tube, fluids, lorazepam, adrenaline, glucose) acronym. While smartphone applications (apps) are increasingly used for these calculations in clinical practice, limited studies have explored their accuracy and safety. AIM: To assess the accuracy of three calculation methods for paediatric emergency drug doses and fluid volumes: a smartphone app, reference charts and traditional calculation methods. The secondary aims were to investigate the effect on the time taken and self-reported stress levels. METHODS: A convenience sample of healthcare professionals from four hospitals contributed. Participants calculated drug and fluid doses for fictional patients using the three different methods. The method and case order were randomised centrally. The study recorded the number of errors made during the calculations, healthcare professionals' self-reported stress levels on a scale of 0 (no stress) to 10 (maximum stress) and the time taken for each case. The app was developed at the direct request of the study team. RESULTS: Ninety-six participants calculated values for six fictional cases, resulting in 576 calculations. Traditional calculation methods showed a statistically significant higher rate of error compared with the use of a smartphone app or reference charts (mean=1, 0, 0, respectively). The smartphone app outperformed both traditional calculation methods and reference charts for time taken and user-reported stress levels. CONCLUSIONS: Traditional methods of 'WETFLAG' drug and fluid calculations are associated with a statistically significant increased risk of error compared with the use of reference charts or smartphone app. The smartphone app proved significantly faster and less stressful to use compared with traditional calculation methods or reference charts.

Have the UK Pediatric Trauma Protocols resulted in a reduction in chest computed tomography imaging for children presenting with major blunt trauma?

Objectives: To observe variation in imaging requests after publication of the Royal College of Radiologists UK Paediatric Trauma Protocols in 2014, recommending limited use of thoracic computed tomography (CT) to appropriately clinically risk stratified children. Method: A retrospective observational study using data from the Trauma Audit & Research Network in the United Kingdom, for children (0-16 years of age) for the years 2012-2021. Percentages were calculated to facilitate comparison between year groups (under 1 year of age, 1-10 years of age, 11-15 years of age), and CT imaging categories reviewed: (1) whole-body CT (WBCT); (2) abdominopelvic CT (CTAP) with chest radiograph (CXR); (3) chest, abdomen, and pelvic CT (CTCAP) with CXR; (4) CTCAP without CXR; and (5) other imaging. Results: Increased use of the recommended protocol (CXR with CTAP) was observed after guidance publication but was not sustained: infants under 1 year old, 0.0% in 2012, 7% in 2017, 0.0% in 2021; 1-10-year-olds, 4% in 2012, 13.9% in 2017, 5.5% in 2021; 11-15-year-olds, 7.1% in 2012, 10.2% in 2017, 6.6% in 2021. Requests for WBCT increased from 2012-2021 (all age groups, 2.4%, 2012, to 5.3%, 2021) and requests for CTCAP were consistently at a higher level than that of the recommended protocol. Conclusion: The increased use of CXR with CTAP after publication of the guidelines, was not sustained with a decreasing trend observed from ∼2017, raising concern for the ionizing radiation burden in this population.

Major trauma presentations and patient outcomes in English hospitals during the COVID-19 pandemic: An observational cohort study.

BACKGROUND: Single-centre studies suggest that successive Coronavirus Disease 2019 (COVID-19)-related "lockdown" restrictions in England may have led to significant changes in the characteristics of major trauma patients. There is also evidence from other countries that diversion of intensive care capacity and other healthcare resources to treating patients with COVID-19 may have impacted on outcomes for major trauma patients. We aimed to assess the impact of the COVID-19 pandemic on the number, characteristics, care pathways, and outcomes of major trauma patients presenting to hospitals in England. METHODS AND FINDINGS: We completed an observational cohort study and interrupted time series analysis including all patients eligible for inclusion in England in the national clinical audit for major trauma presenting between 1 January 2017 and 31 of August 2021 (354,202 patients). Demographic characteristics (age, sex, physiology, and injury severity) and clinical pathways of major trauma patients in the first lockdown (17,510 patients) and second lockdown (38,262 patients) were compared to pre-COVID-19 periods in 2018 to 2019 (comparator period 1: 22,243 patients; comparator period 2: 18,099 patients). Discontinuities in trends for weekly estimated excess survival rate were estimated when lockdown measures were introduced using segmented linear regression. The first lockdown had a larger associated reduction in numbers of major trauma patients (-4,733 (21%)) compared to the pre-COVID period than the second lockdown (-2,754 (6.7%)). The largest reductions observed were in numbers of people injured in road traffic collisions excepting cyclists where numbers increased. During the second lockdown, there were increases in the numbers of people injured aged 65 and over (665 (3%)) and 85 and over (828 (9.3%)). In the second week of March 2020, there was a reduction in level of major trauma excess survival rate (-1.71%; 95% CI: -2.76% to -0.66%) associated with the first lockdown. This was followed by a weekly trend of improving survival until the lifting of restrictions in July 2020 (0.25; 95% CI: 0.14 to 0.35). Limitations include eligibility criteria for inclusion to the audit and COVID status of patients not being recorded. CONCLUSIONS: This national evaluation of the impact of COVID on major trauma presentations to English hospitals has observed important public health findings: The large reduction in overall numbers injured has been primarily driven by reductions in road traffic collisions, while numbers of older people injured at home increased over the second lockdown. Future research is needed to better understand the initial reduction in likelihood of survival after major trauma observed with the implementation of the first lockdown.

Comparison of injury patterns and interventions between adolescent, adult and paediatric trauma cases: a cross-sectional review of TARN data.

OBJECTIVES: The aim is to compare adolescent (10-24.99 years) trauma patterns and interventions to adult (≥25) and paediatric cases (<10) and to identify any transition points. DESIGN AND SETTING: Data were collected from the Trauma and Audit Research Network (TARN) over a 10-year period. We conducted a retrospective cross-sectional analysis. PARTICIPANTS: After exclusions there were 505 162 TARN eligible cases. PRIMARY AND SECONDARY OUTCOME MEASURES: To compare adolescent trauma patterns and interventions to those in paediatric and adult cohorts. Identify transition points for mechanism of injury (MOI) and interventions by individual year over the adolescent age range (10-24.99). RESULTS: Road traffic accidents are the most common MOI in the adolescent group, in contrast to both the paediatric and adult group where falls <2 m are most common. Violence-related injury (shootings and stabbings) are more common in the adolescent group, 9.4% compared with 0.3% and 1.5% in the paediatric and adult groups, respectively. The adolescent grouping had the highest median Injury Severity Score (ISS) and the highest proportion of interventions. The proportion of cases due to stabbing peaked at age 17 (11.8%) becoming the second most common MOI. The median ISS peaked at 13 at age 18. The percentage of cases that fulfil the definition of polytrauma enters double figures (11.8%) at age 15 reaching a peak of 17.6% at age 18. The use of blood products within the first 6 hours remains around 2% (1.6%-2.8%) until age 15 (3.4%), increasing to 4.7% at age 16. CONCLUSIONS: Trauma patterns are more closely aligned between adult and paediatric cohorts than adolescence. The highest proportion of trauma interventions occur in the adolescent population. Analysing the adolescent cohort by year of age identified some common points for when descriptors or outcomes altered in frequency, predominantly between the ages of 15-17 years.

Do Patients with Diabetes Mellitus and Polytrauma Continue to Have Worse Outcomes?

The management of patients with multiple injuries remains challenging. Patients presenting with comorbidities, such as diabetes mellitus, may have additional unpredictable outcomes with increased mortality. Therefore, we aim to investigate the impact of major trauma centres in the UK on the outcomes of polytrauma patients with diabetes. The Trauma Audit and Research Network was used to identify polytrauma patients presenting to centres in England and Wales between 2012 and 2019. In total, 32,345 patients were thereby included and divided into three groups: 2271 with diabetes, 16,319 with comorbidities other than diabetes and 13,755 who had no comorbidities. Despite an overall increase in diabetic prevalence compared to previously published data, mortality was reduced in all groups, but diabetic patient mortality remained higher than in the other groups. Interestingly, increasing Injury Severity Score (ISS) and age were associated with increasing mortality, whereas the presence of diabetes, even when taking into consideration age, ISS and Glasgow Coma Score, led to an increase in the prediction of mortality with an odds ratio of 1.36 (p < 0.0001). The prevalence of diabetes mellitus in polytrauma patients has increased, and diabetes remains an independent risk factor for mortality following polytrauma.

Severe trauma with associated pelvic fractures: The impact of regional trauma networks on clinical outcome.

Lately, the care of severely injured patients in the United Kingdom has undergone a significant transformation. The establishment of regional trauma networks (RTN) with designated Major Trauma Centers (MTCs) and satellite hospitals called Trauma Units (TUs) has centralized the care of severely injured patients in the MTCs. Pelvic fractures are notoriously linked with hypovolemic shock or even death from excessive blood loss. The aim of this prospective cohort study is to compare the profile of severely injured patients with combined pelvic fractures and their mortality between two different distinct eras of an advanced healthcare system. Anonymized consecutive patient records submitted to TARN UK between 2002 and 2017 by NHS England hospitals were analyzed. Records of patients without a pelvic fracture, or with isolated pelvic fractures (no other serious injury with abbreviated injury scale AIS >2) were excluded. All patients with known outcomes were included and were divided into 2 distinct periods (pre-RTN era: between January 2002 and March 2008 (control group); and RTN era April 2013 to June 2017 (study group)). Data from the transition period from April 2008 to March 2013 were excluded to minimize the effect of variations between the developing networks and MTCs during that era. Overall, the study group included 10,641 patients, whereas the control group was 3152 patients, with a median age of 52.4 and 35.1 years and an ISS of 24 and 27 respectively. A systolic blood pressure below 90mmHg was observed in 7.2% of patients in the study group and 10.4% in the control group. A significant increase of the median time to death (from 8hrs to 188hrs) was observed between the two eras. The cumulative mortality of severely injured patients with pelvic fractures decreased significantly from 17.8% to 12.4% (p<0.0001). The recorded improvement of survivorship in the subgroup of severely injured patients with a pelvic fracture (32% lower in the post-RTN than in the pre-RTN period: OR 1.32  (95% CI 1.21 - 1.44), following the first 5 years of established regional trauma networks in NHS England, is encouraging, and should be attributed to a wide range of factors that translate to all levels of trauma care.

Association between major trauma centre care and outcomes of adult patients injured by low falls in England and Wales.

BACKGROUND: Disability and death due to low falls is increasing worldwide and disproportionately affects older adults. Current trauma systems were not designed to suit the needs of these patients. This study assessed the association between major trauma centre (MTC) care and outcomes in adult patients injured by low falls. METHODS: Data were obtained from the Trauma Audit and Research Network on adult patients injured by falls from <2 m between 2017 and 2019 in England and Wales. 30-day survival, length of hospital stay and discharge destination were compared between MTCs and trauma units or local emergency hospitals (TU/LEHs) using an adjusted multiple logistic regression model. RESULTS: 127 334 patients were included, of whom 27.6% attended an MTC. The median age was 79.4 years (IQR 64.5-87.2 years), and 74.2% of patients were aged >65 years. MTC care was not associated with improved 30-day survival (adjusted OR (AOR) 0.91, 95% CI 0.87 to 0.96, p<0.001). Transferred patients had a significant impact on the results. After excluding transferred patients, MTC care was associated with greater odds of 30-day survival (AOR 1.056, 95% CI 1.001 to 1.113, p=0.044). MTC care was also associated with greater odds of 30-day survival in the most severely injured patients (AOR 1.126, 95% CI 1.04 to 1.22, p=0.002), but not in patients aged >65 years (AOR 1.038, 95% CI 0.982 to 1.097, p=0.184). CONCLUSION: MTC care was not associated with improved survival compared with TU/LEH care in the whole cohort. Patients who were transferred had a significant impact on the results. In patients who are not transferred, MTC care is associated with greater odds of 30-day survival in the whole cohort and in the most severely injured patients. Future research must determine the optimum means of identifying patients in need of higher-level care, the components of care which improve patient outcomes, develop patient-focused outcomes which reflect the characteristics and priorities of contemporary trauma patients, and investigate the need for transfer in specific subgroups of patients.

Comparison of trauma care structures, processes and outcomes between the English National Health Service and Quebec, Canada.

BACKGROUND: Comparisons across trauma systems are key to identifying opportunities to improve trauma care. We aimed to compare trauma service structures, processes and outcomes between the English National Health Service (NHS) and the province of Quebec, Canada. METHODS: We conducted a multicentre cohort study including admissions of patients aged older than 15 years with major trauma to major trauma centres (MTCs) from 2014/15 to 2016/17. We compared structures descriptively, and time to MTC and time in the emergency department (ED) using Wilcoxon tests. We compared mortality, and hospital and intensive care unit (ICU) length of stay (LOS) using multilevel logistic regression with propensity score adjustment, stratified by body region of the worst injury. RESULTS: The sample comprised 36 337 patients from the NHS and 6484 patients from Quebec. Structural differences in the NHS included advanced prehospital medical teams (v. "scoop and run" in Quebec), helicopter transport (v. fixed-wing aircraft) and trauma team leaders. The median time to an MTC was shorter in Quebec than in the NHS for direct transports (1 h v. 1.5 h, p < 0.001) but longer for transfers (2.5 h v. 6 h, p < 0.001). Time in the ED was longer in Quebec than in the NHS (6.5 h v. 4.0 h, p < 0.001). The adjusted odds of death were higher in Quebec for head injury (odds ratio [OR] 1.28, 95% confidence interval [CI] 1.09-1.51) but lower for thoracoabdominal injuries (OR 0.69, 95% CI 0.52-0.90). The adjusted median hospital LOS was longer for spine, torso and extremity injuries in the NHS than in Quebec, and the median ICU LOS was longer for spine injuries. CONCLUSION: We observed significant differences in the structure of trauma care, delays in access and risk-adjusted outcomes between Quebec and the NHS. Future research should assess associations between structures, processes and outcomes to identify opportunities for quality improvement.

A national study of 23 major trauma centres to investigate the effect of frailty on clinical outcomes in older people admitted with serious injury in England (FiTR 1): a multicentre observational study.

BACKGROUND: Older people are the largest group admitted to hospital with serious injuries. Many older people are living with frailty, a risk factor for poor recovery. We aimed to examine the effect of preinjury frailty on outcomes. METHODS: In this multicentre observational study (FiTR 1), we extracted prospectively collected data from all 23 adult major trauma centres in England on older people (aged ≥65 years) admitted with serious injuries over a 2·5 year period from the Trauma Audit and Research Network (TARN) database. Geriatricians assessed the preinjury Clinical Frailty Scale (CFS), a 9-point scale of fitness and frailty, with a score of 1 indicating a patient is very fit and a score of 9 indicating they are terminally ill. The primary outcome was inpatient mortality, with patients censored at hospital discharge. We used a multi-level Cox regression model fitted with adjusted hazards ratios (aHRs) to assess the association between CFS and mortality, with CFS scores being grouped as follows: a score of 1-2 indicated patients were fit; a score of 3 indicated patients were managing well; and a score of 4-8 indicated patients were living with frailty (4 being very mild, 5 being mild, 6 being moderate, and 7-8 being severe). FINDINGS: Between March 31, 2019, and Oct 31, 2021, 193 156 patients had records were held by TARN, of whom 16 504 had eligible records. Median age was 81·9 years (IQR 74·7-88·0), 9200 (55·7%) were women, and 7304 (44·3%) were men. Of 16 438 patients with a CFS score of 1-8, 11 114 (67·6%) were living with frailty (CFS of 4-8). 1660 (10·1%) patients died during their hospital stay, with a median time from admission to death of 9 days (IQR 4-18). Compared in patients with a CFS score of 1-2, risk of inpatient death was increased in those managing well (CFS score of 3; aHR 1·82 [95% CI 1·39-2·40]), living with very mild frailty (CFS score of 4: 1·99 [1·51-2·62]), living with mild frailty (CFS score of 5: 2·61 [1·99-3·43]), living with moderate frailty (CFS score of 6: 2·97 [2·26-3·90]), and living with severe frailty (CFS score of 7-8: 4·03 [3·04-5·34]). INTERPRETATION: Our findings support inclusion of the CFS in trauma pathways to aid patient management. Additionally, people who exercise regularly (CFS of 1-2) have better outcomes than those with lower activity levels (CFS of ≥3), supporting exercise as an intervention to improve trauma outcomes. FUNDING: None.

A national study of 23 major trauma centres to investigate the effect of a geriatrician assessment on clinical outcomes in older people admitted with serious injury in England (FiTR 2): a multicentre observational cohort study.

BACKGROUND: Older people are at the greatest risk of poor outcomes after serious injury. Evidence is limited for the benefit of assessment by a geriatrician in trauma care. We aimed to determine the effect of geriatrician assessment on clinical outcomes for older people admitted to hospital with serious injury. METHODS: In this multicentre observational study (FiTR 2), we extracted prospectively collected data on older people (aged ≥65 years) admitted to the 23 major trauma centres in England over a 2·5 year period from the Trauma Audit and Research Network (TARN) database. We examined the effect of a geriatrician assessment within 72 h of admission on the primary outcome of inpatient mortality in older people admitted to hospital with serious injury, with patients censored at discharge. We analysed data using a multi-level Cox regression model and estimated adjusted hazard ratios (aHRs). FINDINGS: Between March 31, 2019, and Oct 31, 2021, 193 156 patients had records held by TARN, of whom 35 490 were included in these analyses. Median age was 81·4 years (IQR 74·1-87·6), 19 468 (54·9%) were female, and 16 022 (45·1%) were male. 28 208 (79·5%) patients had experienced a fall from less than 2 m. 16 504 (46·5%) people received a geriatrician assessment. 4419 (12·5%) patients died during hospital stay, with a median time from admission to death of 6 days (IQR 2-14). Of those who died, 1660 (37·6%) had received a geriatrician assessment and 2759 (62·4%) had not (aHR 0·43 [95% CI 0·40-0·46]; p<0·0001). INTERPRETATION: Geriatrician assessment was associated with a reduced risk of death for seriously injured older people. These data support routine provision of geriatrician assessment in trauma care. Future research should explore the key components of a geriatrician assessment paired with a health economic evaluation. FUNDING: None.

Regional variation in the provision of major trauma services for the older injured patient.

INTRODUCTION: The establishment of national trauma networks have resulted in significant benefits to injured patients. Older people are the majority of major trauma patients and there is need to study variations in care and performance against clinical metrics for them. We aim to describe this patient group in terms of injury, demographics, episode of care assessment and variation between component regions of the Major Trauma Network of England and Wales. METHOD: The Trauma Audit and Research Network (TARN) database was analysed from April 2017 to March 2019. Patients aged 65 years and above with injury severity score (ISS) greater than eight were selected for analysis. Patients were compared by care pathway in terms of first and second treating hospitals and by demographics, injury mechanism, severity, physiology at arrival to hospital (including Glasgow Coma Score (GCS)) and mortality, where known, at discharge. RESULTS: Fifty-three thousand three hundred and forty-seven older injured patients (median age 82.5 years and 58.2% female), were treated in 165 hospitals within the 17 regional trauma networks over the two-year study period. Aside from GCS and gender, all other patient characteristics were significantly different between networks and specifically, a large variation between the network with the highest proportion of older patients (60.4%) and that with a preponderance of younger patients (40.2%) is seen. 84% of cases were due to a fall <2 m and 36.7% of cases had a brain injury. 73.5% of cases had one or more comorbidities. DISCUSSION: We have increased the understanding of how older patients contribute to and are managed by a national trauma service. We have demonstrated variation in numbers and patient characteristics throughout regional trauma networks. We have detailed the whole patient episode, allowing us to comment on disparities in management such as senior review and access to specialist clinical care settings. Older patients dominate United Kingdom major trauma and considerable variations and shortfalls have been identified. Work is needed to focus on the whole clinical episode for these patients both to improve outcome and patient experience but to also to ensure sustainable clinical care in a resource deplete era.

Sex-disaggregated analysis of the injury patterns, outcome data and trapped status of major trauma patients injured in motor vehicle collisions: a prespecified analysis of the UK trauma registry (TARN).

OBJECTIVES: To identify the differences between women and men in the probability of entrapment, frequency of injury and outcomes following a motor vehicle collision. Publishing sex-disaggregated data, understanding differential patterns and exploring the reasons for these will assist with ensuring equity of outcomes especially in respect to triage, rescue and treatment of all patients. DESIGN: We examined data from the Trauma Audit and Research Network (TARN) registry to explore sex differences in entrapment, injuries and outcomes. We explored the relationship between age, sex and trapped status using multivariate logistical regression. SETTING: TARN is a UK-based trauma registry covering England and Wales. PARTICIPANTS: We examined data for 450 357 patients submitted to TARN during the study period (2012-2019), of which 70 027 met the inclusion criteria. There were 18 175 (26%) female and 51 852 (74%) male patients. PRIMARY AND SECONDARY OUTCOME MEASURES: We report difference in entrapment status, injury and outcome between female and male patients. For trapped patients, we examined the effect of sex and age on death from any cause. RESULTS: Female patients were more frequently trapped than male patients (female patients (F) 15.8%, male patients (M) 9.4%; p<0.0001). Trapped male patients more frequently suffered head (M 1318 (27.0%), F 578 (20.1%)), face, (M 46 (0.9%), F 6 (0.2%)), thoracic (M 2721 (55.8%), F 1438 (49.9%)) and limb injuries (M 1744 (35.8%), F 778 (27.0%); all p<0.0001). Female patients had more injuries to the pelvis (F 420 (14.6%), M 475 (9.7%); p<0.0001) and spine (F 359 (12.5%), M 485 (9.9%); p=0.001). Following adjustment for the interaction between age and sex, injury severity score, Glasgow Coma Scale and the Charlson Comorbidity Index, no difference in mortality was found between female and male patients. CONCLUSIONS: There are significant differences between female and male patients in the frequency at which patients are trapped and the injuries these patients sustain. This sex-disaggregated data may help vehicle manufacturers, road safety organisations and emergency services to tailor responses with the aim of equitable outcomes by targeting equal performance of safety measures and reducing excessive risk to one sex or gender.

Do entrapment, injuries, outcomes and potential for self-extrication vary with age? A pre-specified analysis of the UK trauma registry (TARN).

BACKGROUND: Motor vehicle collisions (MVCs), particularly those associated with entrapment, are a common cause of major trauma. Current extrication methods are focused on spinal movement minimisation and mitigation, but for many patients self-extrication may be an appropriate alternative. Older drivers and passengers are increasingly injured in MVCs and may be at an increased risk of entrapment and its deleterious effects. The aim of this study is to describe the injuries, trapped status, outcomes, and potential for self-extrication for patients following an MVC across a range of age groups. METHODS: This is a retrospective study using the Trauma Audit and Research Network (TARN) database. Patients were included if they were admitted to an English hospital following an MVC from 2012 to 2019. Patients were excluded when their outcomes were not known or if they were secondary transfers. Simple descriptive analysis was used across the age groups: 16-59, 60-69, 70-79 and 80+ years. Logistic regression was performed to develop a model with known confounders, considering the odds of death by age group, and examining any interaction between age and trapped status with mortality. RESULTS: 70,027 patients met the inclusion criteria. Older patients were more likely to be trapped and to die following an MVC (p < 0.0001). Head, abdominal and limb injuries were more common in the young with thoracic and spinal injuries being more common in older patients (all p < 0.0001). No statistical difference was found between the age groups in relation to ability to self-extricate. After adjustment for confounders, the 80 + age group were more likely to die if they were trapped; adjusted OR trapped 30.2 (19.8-46), not trapped 24.2 (20.1-29.2). CONCLUSIONS: Patients over the age of 80 are more likely to die when trapped following an MVC. Self-extrication should be considered the primary route of egress for patients of all ages unless it is clearly impracticable or unachievable. For those patients who cannot self-extricate, a minimally invasive extrication approach should be employed to minimise entrapment time.

Imputation strategies for missing baseline neurological assessment covariates after traumatic brain injury: A CENTER-TBI study.

Statistical models for outcome prediction are central to traumatic brain injury research and critical to baseline risk adjustment. Glasgow coma score (GCS) and pupil reactivity are crucial covariates in all such models but may be measured at multiple time points between the time of injury and hospital and are subject to a variable degree of unreliability and/or missingness. Imputation of missing data may be undertaken using full multiple imputation or by simple substitution of measurements from other time points. However, it is unknown which strategy is best or which time points are more predictive. We evaluated the pseudo-R2 of logistic regression models (dichotomous survival) and proportional odds models (Glasgow Outcome Score-extended) using different imputation strategies on the The Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study dataset. Substitution strategies were easy to implement, achieved low levels of missingness (<< 10%) and could outperform multiple imputation without the need for computationally costly calculations and pooling multiple final models. While model performance was sensitive to imputation strategy, this effect was small in absolute terms and clinical relevance. A strategy of using the emergency department discharge assessments and working back in time when these were missing generally performed well. Full multiple imputation had the advantage of preserving time-dependence in the models: the pre-hospital assessments were found to be relatively unreliable predictors of survival or outcome. The predictive performance of later assessments was model-dependent. In conclusion, simple substitution strategies for imputing baseline GCS and pupil response can perform well and may be a simple alternative to full multiple imputation in many cases.

Mortality in adolescent trauma: a comparison of children's, mixed and adult major trauma centres.

OBJECTIVE: We aimed to compare adolescent mortality rates between different types of major trauma centre (MTC or level 1; adult, children's and mixed). METHODS: Data were obtained from TARN (Trauma Audit Research Network) from English sites over a 6-year period (2012-2018), with adolescence defined as 10-24.99 years. Results are presented using descriptive statistics. Patient characteristics were compared using the Kruskal-Wallis test with Dunn's post-hoc analysis for pairwise comparison and χ2 test for categorical variables. RESULTS: 21 033 cases met inclusion criteria. Trauma-related 30-day crude mortality rates by MTC type were 2.5% (children's), 4.4% (mixed) and 4.9% (adult). Logistic regression accounting for injury severity, mechanism of injury, physiological parameters and 'hospital ID', resulted in adjusted odds of mortality of 2.41 (95% CI 1.31 to 4.43; p=0.005) and 1.85 (95% CI 1.03 to 3.35; p=0.041) in adult and mixed MTCs, respectively when compared with children's MTCs. In three subgroup analyses the same trend was noted. In adolescents aged 14-17.99 years old, those managed in a children's MTC had the lowest mortality rate at 2.5%, compared with 4.9% in adult MTCs and 4.4% in mixed MTCs (no statistical difference between children's and mixed). In cases of major trauma (Injury Severity Score >15) the adjusted odds of mortality were also greater in the mixed and adult MTC groups when compared with the children's MTC. Median length of stay (LoS) and intensive care unit LoS were comparable for all MTC types. Patients managed in children's MTCs were less likely to have a CT scan (46.2% vs 62.8% mixed vs 64% adult). CONCLUSIONS: Children's MTC have lower crude and adjusted 30-day mortality rates for adolescent trauma. Further research is required in this field to identify the factors that may have influenced these findings.

A comparison of the demographics, injury patterns and outcome data for patients injured in motor vehicle collisions who are trapped compared to those patients who are not trapped.

BACKGROUND: Motor vehicle collisions (MVCs) are a common cause of major trauma and death. Following an MVC, up to 40% of patients will be trapped in their vehicle. Extrication methods are focused on the prevention of secondary spinal injury through movement minimisation and mitigation. This approach is time consuming and patients may have time-critical injuries. The purpose of this study is to describe the outcomes and injuries of those trapped following an MVC: this will help guide meaningful patient-focused interventions and future extrication strategies. METHODS: We undertook a retrospective database study using the Trauma Audit and Research Network database. Patients were included if they were admitted to an English hospital following an MVC from 2012 to 2018. Patients were excluded when their outcomes were not known or if they were secondary transfers. RESULTS: This analysis identified 426,135 cases of which 63,625 patients were included: 6983 trapped and 56,642 not trapped. Trapped patients had a higher mortality (8.9% vs 5.0%, p < 0.001). Spinal cord injuries were rare (0.71% of all extrications) but frequently (50.1%) associated with other severe injuries. Spinal cord injuries were more common in patients who were trapped (p < 0.001). Injury Severity Score (ISS) was higher in the trapped group 18 (IQR 10-29) vs 13 (IQR 9-22). Trapped patients had more deranged physiology with lower blood pressures, lower oxygen saturations and lower Glasgow Coma Scale, GCS (all p < 0.001). Trapped patients had more significant injuries of the head chest, abdomen and spine (all p < 0.001) and an increased rate of pelvic injures with significant blood loss, blood loss from other areas or tension pneumothorax (all p < 0.001). CONCLUSION: Trapped patients are more likely to die than those who are not trapped. The frequency of spinal cord injuries is low, accounting for < 0.7% of all patients extricated. Patients who are trapped are more likely to have time-critical injuries requiring intervention. Extrication takes time and when considering the frequency, type and severity of injuries reported here, the benefit of movement minimisation may be outweighed by the additional time taken. Improved extrication strategies should be developed which are evidence-based and allow for the expedient management of other life-threatening injuries.

Cross-validation of two prognostic trauma scores in severely injured patients.

INTRODUCTION: Trauma scoring systems are important tools for outcome prediction and severity adjustment that informs trauma quality assessment and research. Discrimination and precision of such systems is tested in validation studies. The German TraumaRegister DGU® (TR-DGU) and the Trauma Audit and Research Network (TARN) from the UK agreed on a cross-validation study to validate their prediction scores (RISC II and PS14, respectively). METHODS: Severe trauma patients with an Injury Severity Score (ISS) ≥ 9 documented in 2015 and 2016 were selected in both registries (primary admissions only). The predictive scores from each registry were applied to the selected data sets. Observed and predicted mortality were compared to assess precision; area under the receiver operating characteristic curve was used for discrimination. Hosmer-Lemeshow statistic was calculated for calibration. A subgroup analysis including patients treated in intensive care unit (ICU) was also carried out. RESULTS: From TR-DGU, 40,638 patients were included (mortality 11.7%). The RISC II predicted mortality was 11.2%, while PS14 predicted 16.9% mortality. From TARN, 64,622 patients were included (mortality 9.7%). PS14 predicted 10.6% mortality, while RISC II predicted 17.7%. Despite the identical cutoff of ISS ≥ 9, patient groups from both registries showed considerable difference in need for intensive care (88% versus 18%). Subgroup analysis of patients treated on ICU showed nearly identical values for observed and predicted mortality using RISC II. DISCUSSION: Each score performed well within its respective registry, but when applied to the other registry a decrease in performance was observed. Part of this loss of performance could be explained by different development data sets: the RISC II is mainly based on patients treated in an ICU, while the PS14 includes cases mainly cared for outside ICU with more moderate injury severity. This is according to the respective inclusion criteria of the two registries. CONCLUSION: External validations of prediction models between registries are needed, but may show that prediction models are not fully transferable to other health-care settings.

Helicopter and ground emergency medical services transportation to hospital after major trauma in England: a comparative cohort study.

BACKGROUND: The utilization of helicopter emergency medical services (HEMS) in modern trauma systems has been a source of debate for many years. This study set to establish the true impact of HEMS in England on survival for patients with major trauma. METHODS: A comparative cohort design using prospectively recorded data from the UK Trauma Audit and Research Network registry. 279 107 patients were identified between January 2012 and March 2017. The primary outcome measure was risk adjusted in-hospital mortality within propensity score matched cohorts using logistic regression analysis. Subset analyses were performed for subjects with prehospital Glasgow Coma Scale <8, respiratory rate <10 or >29 and systolic blood pressure <90. RESULTS: The analysis was based on 61 733 adult patients directly admitted to major trauma centers: 54 185 ground emergency medical services (GEMS) and 7548 HEMS. HEMS patients were more likely male, younger, more severely injured, more likely to be victims of road traffic collisions and intubated at scene. Crude mortality was higher for HEMS patients. Logistic regression demonstrated a 15% reduction in the risk adjusted odds of death (OR=0.846; 95% CI 0.684 to 1.046) in favor of HEMS. When analyzed for patients previously noted to benefit most from HEMS, the odds of death were reduced further but remained statistically consistent with no effect. Sensitivity analysis on 5685 patients attended by a doctor on scene but transported by GEMS demonstrated a protective effect on mortality versus the standard GEMS response (OR 0.77; 95% CI 0.62 to 0.95). DISCUSSION: This prospective, level 3 cohort analysis demonstrates a non-significant survival advantage for patients transported by HEMS versus GEMS. Despite the large size of the cohort, the intrinsic mismatch in patient demographics limits the ability to statistically assess HEMS true benefit. It does, however, demonstrate an improved survival for patients attended by doctors on scene in addition to the GEMS response. Improvements in prehospital data and increased trauma unit reporting are required to accurately assess HEMS clinical and cost-effectiveness.

A study of cardiorespiratory related mortality as a result of exposure to black carbon.

INTRODUCTION: Air pollution is a global phenomenon which invariably leads to a serious environmental and health related sequalae. "Black carbon" (BC), a subset of fine particulate matter ≤2.5 µm (PM2.5), is a fossil fuel emission by-product and has more recently been recognized as a major health hazard. The objective of this study is to statistically analyze the BC concentration and its correlation with cardiorespiratory related mortality and to estimate the benefits of BC reduction on the health of the population in the capital city of Tehran. METHODS: We analyzed the ambient air BC concentration and its correlation with cardiorespiratory related mortality and conducted health impact assessment of BC in Tehran (Jan 2018-Jan 2019). The data pertaining to BC concentration was obtained from Tehran's four major pollution monitoring stations. The mortality data was obtained from Tehran's cemetery registry. We calculated and analyzed BC concentration statistics including the mean, standard deviation, coefficient of variation, skewness, and kurtosis. We then assessed the cross-correlation and temporal relationship (0-7 days) between the daily mean concentration of BC for the entire city and cardiorespiratory related mortality. The BenMAP software was utilized to estimate the potential reduction in cardiorespiratory related mortality rates if BC concentration is reduced. Three hypothetical scenarios were employed in the analysis, utilizing the BenMAP software: (I) BC concentration was completely removed from the ambient air; (II) BC concentration was eliminated, and the remaining (non-BC portion of) PM2.5 concentration was reverted to the United States Environmental Protection Agency (EPA)'s standard level (i.e., 35 µg/m3); and (III) The BC emission during the night (22:00 h-6:00 h, when heavy-duty vehicles (HDVs) are allowed to commute in the city) was distributed throughout the whole day. Since the planetary boundary layer during daytime is much higher than that of nighttime, with the same rate of emission, lower concentrations are spread during the whole day. RESULTS: The trend of BC concentration variation revealed a persistently higher emission of BC during the nighttime, which is consistent with the large-scale operation of HDVs during these hours in the city of Tehran. We observed a direct correlation between BC concentration and cardiorespiratory related mortality. Analysis also showed a 1.4-day lag period from the time of exposure to BC polluted air and respiratory related deaths, and 2 days for cardiovascular related deaths. As a result, the reduction in BC has significant beneficial effects in reducing potentially preventable cardiorespiratory related mortality. The aforementioned three scenarios for age groups of 30 and above yielded the following results: (I) 11,369 (126 per 100,000 population), (II) 15,386 (171 per 100,000 population), and (III) 2552 (28 per 100,000 population) potentially preventable all-cause (including cardiorespiratory) related deaths annually. CONCLUSIONS: The BC concentration is relatively high in Tehran and HDVs have a major role in emission of this pollutant. A direct correlation between BC concentration and cardiorespiratory related mortality is observed. There are considerable health benefits in reducing BC concentration in this city. Our findings highlight the urgent need to actively curtail emissions of this harmful pollutant. This can be achieved through utilizing control mechanisms such as particulate filters or amending traffic laws.