Evaluating the validity of multiple imputation for missing physiological data in the national trauma data bank

Survival bias in pediatric hemorrhagic shock: Are we misrepresenting the data?

BACKGROUND

Studies of hemorrhage following pediatric injury often use the occurrence of transfusion as a surrogate definition for the clinical need for a transfusion. Using this approach, patients who are bleeding but die before receiving a transfusion are misclassified as not needing a transfusion. In this study, we aimed to evaluate the potential for this survival bias and to estimate its presence among a retrospective observational cohort of children and adolescents who died from injury.

METHODS

We obtained patient, injury, and resuscitation characteristics from the 2017 to 2020 Trauma Quality Improvement Program database of children and adolescents (younger than 18 years) who arrived with or without signs of life and died. We performed univariate analysis and a multivariable logistic regression to analyze the association between the time to death and the occurrence of transfusion within 4 hours after hospital arrival controlling for initial vital signs, injury type, body regions injured, and scene versus transfer status.

RESULTS

We included 6,063 children who died from either a blunt or penetrating injury. We observed that children who died within 15 minutes had lower odds of receiving a transfusion (odds ratio, 0.1; 95% confidence interval, 0.1-0.2) compared with those who survived longer. We estimated that survival bias that occurs when using transfusion administration alone to define hemorrhagic shock may occur in up to 11% of all children who died following a blunt or penetrating injury but less than 1% of all children managed as trauma activations.

CONCLUSION

Using the occurrence of transfusion alone may underestimate the number of children who die from uncontrolled hemorrhage early after injury. Additional variables than just transfusion administration are needed to more accurately identify the presence of hemorrhagic shock among injured children and adolescents.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

Multiple Imputation of Missing Race/Ethnicity Information in the National Assisted Reproductive Technology Surveillance System

Background: Missing race/ethnicity data are common in many surveillance systems and registries, which may limit complete and accurate assessments of racial and ethnic disparities. Centers for Disease Control and Prevention's National Assisted Reproductive Technology (ART) Surveillance System (NASS) has a congressional mandate to collect data on all ART cycles performed by fertility clinics in the United States and provides valuable information on ART utilization and treatment outcomes. However, race/ethnicity data are missing for many ART cycles in NASS. Materials and Methods: We multiply imputed missing race/ethnicity data using variables from NASS and additional zip code-level race/ethnicity information in U.S. Census data. To evaluate imputed data quality, we generated training data by imposing missing values on known race/ethnicity under missing at random assumption, imputed, and examined the relationship between race/ethnicity and the rate of stillbirth per pregnancy. Results: The distribution of imputed race/ethnicity was comparable to the reported one with the largest difference of 0.53% for non-Hispanic Asian. Our imputation procedure was well calibrated and correctly identified that 89.91% (standard error = 0.18) of known race/ethnicity values on average in training data. Compared to complete-case analysis, using multiply imputed data reduced bias of parameter estimates (the range of bias for stillbirth per pregnancy across race/ethnicity groups is 0.02%-0.18% for imputed data analysis, versus 0.04%-0.66% for complete-case analysis) and yielded narrower confidence intervals. Conclusions: Our results underscore the importance of collecting complete race/ethnicity information for ART surveillance. However, when the missingness exists, multiply imputed race/ethnicity can improve the accuracy and precision of health outcomes estimated across racial/ethnic groups.

On Scene Injury Severity Prediction (OSISP) model for trauma developed using the Swedish Trauma Registry

BACKGROUND

Providing optimal care for trauma, the leading cause of death for young adults, remains a challenge e.g., due to field triage limitations in assessing a patient's condition and deciding on transport destination. Data-driven On Scene Injury Severity Prediction (OSISP) models for motor vehicle crashes have shown potential for providing real-time decision support. The objective of this study is therefore to evaluate if an Artificial Intelligence (AI) based clinical decision support system can identify severely injured trauma patients in the prehospital setting.

METHODS

The Swedish Trauma Registry was used to train and validate five models - Logistic Regression, Random Forest, XGBoost, Support Vector Machine and Artificial Neural Network - in a stratified 10-fold cross validation setting and hold-out analysis. The models performed binary classification of the New Injury Severity Score and were evaluated using accuracy metrics, area under the receiver operating characteristic curve (AUC) and Precision-Recall curve (AUCPR), and under- and overtriage rates.

RESULTS

There were 75,602 registrations between 2013-2020 and 47,357 (62.6%) remained after eligibility criteria were applied. Models were based on 21 predictors, including injury location. From the clinical outcome, about 40% of patients were undertriaged and 46% were overtriaged. Models demonstrated potential for improved triaging and yielded AUC between 0.80-0.89 and AUCPR between 0.43-0.62.

CONCLUSIONS

AI based OSISP models have potential to provide support during assessment of injury severity. The findings may be used for developing tools to complement field triage protocols, with potential to improve prehospital trauma care and thereby reduce morbidity and mortality for a large patient population.

Relationship between systolic blood pressure and mortality in older vs younger trauma patients - a retrospective multicentre observational study

BACKGROUND

The population of older trauma patients is increasing. Those patients have heterogeneous presentations and need senior-friendly triaging tools. Systolic blood pressure (SBP) is commonly used to assess injury severity, and some authors advocated adjusting SBP threshold for older patients. We aimed to describe and compare the relationship between mortality and SBP in older trauma patients and their younger counterparts.

METHODS

We included patients admitted to three level-I trauma centres and performed logistic regressions with age and SBP to obtain mortality curves. Multivariable Logistic regressions were performed to measure the association between age and mortality at different SBP ranges. Subgroup analyses were conducted for major trauma and severe traumatic brain injury admissions.

RESULTS

A total of 47,661 patients were included, among which 12.9% were aged 65-74 years and 27.3% were ≥ 75 years. Overall mortality rates were 3.9%, 8.1%, and 11.7% in the groups aged 16-64, 65-74, and ≥ 75 years, respectively. The relationship between prehospital SBP and mortality was nonlinear (U-shape), mortality increased with each 10 mmHg SBP decrement from 130 to 50 mmHg and each 10-mmHg increment from 150 to 220 mmHg across all age groups. Older patients were at higher odd for mortality in all ranges of SBP. The highest OR in patients aged 65-74 years was 3.67 [95% CI: 2.08-6.45] in the 90-99 mmHg SBP range and 7.92 [95% CI: 5.13-12.23] for those aged ≥ 75 years in the 100-109 mmHg SBP range.

CONCLUSION

The relationship between SBP and mortality is nonlinear, regardless of trauma severity and age. Older age was associated with a higher odd of mortality at all SBP points. Future triage tools should therefore consider SBP as a continuous rather than a dichotomized predictor.

Effect of age on the association between the Glasgow Coma Scale and the anatomical brain lesion severity: a retrospective multicentre study

Background and importance Older adults are at higher risk of undertriage and mortality following a traumatic brain injury (TBI). Early identification and accurate triage of severe cases is therefore critical. However, the Glasgow Coma Scale (GCS) might lack sensitivity in older patients. Objective This study investigated the effect of age on the association between the GCS and TBI severity. Design, settings, and participants This multicentre retrospective cohort study (2003-2017) included TBI patients aged ≥16 years with an Abbreviated Injury Scale (AIS of 3, 4 or 5). Older adults were defined as aged 65 and over. Outcomes measure and analysis Median GCS score were compared between older and younger adults, within subgroups of similar AIS. Multivariable logistic regressions were computed to assess the association between age and mortality. The primary analysis comprised patients with isolated TBI, and secondary analysis included patients with multiple trauma. Main results A total of 12 562 patients were included, of which 9485 (76%) were isolated TBIs. Among those, older adults represented 52% ( n  = 4931). There were 22, 27 and 51% of older patients with an AIS-head of 3, 4 and 5 respectively compared to 32, 25 and 43% among younger adults. Within the different subgroups of patients, median GCS scores were higher in older adults: 15 (14-15) vs. 15 (13-15), 15 (14-15) vs. 14 (13-15), 15 (14-15) vs. 14 (8-15), for AIS-head 3, 4 and 5 respectively (all P  < 0.0001). Older adults had increased odds of mortality compared to their younger counterparts at all AIS-head levels: AIS-head = 3 [odds ratio (OR) = 2.9, 95% confidence interval (CI) 1.6-5.5], AIS-head = 4, (OR = 2.7, 95% CI 1.6-4.7) and AIS-head = 5 (OR = 2.6, 95% CI 1.9-3.6) TBI (all P  < 0.001). Similar results were found among patients with multiple trauma. Conclusions In this study, among TBI patients with similar AIS-head score, there was a significant higher median GCS in older patients compared to younger patients.

Evaluating the effectiveness of a multifaceted intervention to reduce low-value care in adults hospitalized following trauma: a protocol for a pragmatic cluster randomized controlled trial

BACKGROUND

While simple Audit & Feedback (A&F) has shown modest effectiveness in reducing low-value care, there is a knowledge gap on the effectiveness of multifaceted interventions to support de-implementation efforts. Given the need to make rapid decisions in a context of multiple diagnostic and therapeutic options, trauma is a high-risk setting for low-value care. Furthermore, trauma systems are a favorable setting for de-implementation interventions as they have quality improvement teams with medical leadership, routinely collected clinical data, and performance-linked to accreditation. We aim to evaluate the effectiveness of a multifaceted intervention for reducing low-value clinical practices in acute adult trauma care.

METHODS

We will conduct a pragmatic cluster randomized controlled trial (cRCT) embedded in a Canadian provincial quality assurance program. Level I-III trauma centers (n = 30) will be randomized (1:1) to receive simple A&F (control) or a multifaceted intervention (intervention). The intervention, developed using extensive background work and UK Medical Research Council guidelines, includes an A&F report, educational meetings, and facilitation visits. The primary outcome will be the use of low-value initial diagnostic imaging, assessed at the patient level using routinely collected trauma registry data. Secondary outcomes will be low-value specialist consultation, low-value repeat imaging after a patient transfer, unintended consequences, determinants for successful implementation, and incremental cost-effectiveness ratios.

DISCUSSION

On completion of the cRCT, if the intervention is effective and cost-effective, the multifaceted intervention will be integrated into trauma systems across Canada. Medium and long-term benefits may include a reduction in adverse events for patients and an increase in resource availability. The proposed intervention targets a problem identified by stakeholders, is based on extensive background work, was developed using a partnership approach, is low-cost, and is linked to accreditation. There will be no attrition, identification, or recruitment bias as the intervention is mandatory in line with trauma center designation requirements, and all outcomes will be assessed with routinely collected data. However, investigators cannot be blinded to group allocation and there is a possibility of contamination bias that will be minimized by conducting intervention refinement only with participants in the intervention arm.

TRIAL REGISTRATION

This protocol has been registered on ClinicalTrials.gov (February 24, 2023, # NCT05744154 ).

Evaluation of Missing Prehospital Physiological Values in Injured Children and Adolescents

INTRODUCTION

Prehospital vital signs and the Glasgow Coma Scale score are often missing in clinical practice and not recorded in trauma databases. Our study aimed to identify factors associated with missing prehospital physiological values, including systolic blood pressure, heart rate, respiratory rate, peripheral oxygen saturation, and Glasgow Coma Scale.

METHODS

We used our hospital trauma registry to obtain patient, injury, resuscitation, and transportation characteristics for injured children and adolescents (age <15 y). We evaluated the association of missing documentation of prehospital values with other patient, injury, transportation, and resuscitation characteristics using multivariable regression. We standardized vital sign values using age-adjusted z-scores.

RESULTS

The odds of a missing physiological value decreased with age (odds ratio [OR] = 0.9, 95% confidence interval [CI] = 0.9, 0.9) and were higher when prehospital cardiopulmonary resuscitation was required (OR = 3.3, 95% CI = 1.9, 5.7). Among the physiological values considered, we observed the highest odds of missingness of systolic blood pressure, respiratory rate, and oxygen saturation. The odds of observing normal emergency department physiological values were lower when prehospital physiological values were missing (OR = 0.9, 95% CI = 0.9, 1.0; P = 0.04).

CONCLUSIONS

Missing prehospital physiological values were associated with younger age and cardiopulmonary resuscitation among the injured children treated at our hospital. Measurement and documentation of physiological variables of patients with these characteristics should be targeted.

Time is tissue: Barriers to timely transfusion after pediatric injury

ABSTRACT

Strategies to improve outcomes among children and adolescents in hemorrhagic shock have primarily focused on component resuscitation, pharmaceutical coagulation adjuncts, and hemorrhage control techniques. Many of these strategies have been associated with better outcomes in children, but the barriers to their use and the impact of timely use on morbidity and mortality have received little attention. Because transfusion is uncommon in injured children, few studies have identified and described barriers to the processes of using these interventions in bleeding patients, processes that move from the decision to transfuse, to obtaining the necessary blood products and adjuncts, and to delivering them to the patient. In this review, we identify and describe the steps needed to ensure timely blood transfusion and propose practices to minimize barriers in this process. Given the potential impact of time on hemorrhage associated outcomes, ensuring timely intervention may have a similar or greater impact than the interventions themselves.

Direct to OR resuscitation of abdominal trauma: An NTDB propensity matched outcomes study

BACKGROUND

Direct to operating room resuscitation (DOR) is used by some trauma centers for severely injured trauma patients as an approach to minimize time to hemorrhage control. It is unknown whether this strategy results in favorable outcomes. We hypothesized that utilization of an emergency department operating room (EDOR) for resuscitation of patients with abdominal trauma at an urban Level I trauma center would be associated with decreased time to laparotomy and improved outcomes.

METHODS

We included patients 15 years or older with abdominal trauma who underwent emergent laparotomy within 120 minutes of arrival both at our institution and within a National Trauma Data Bank sample between 2007 to 2019 and 2013 to 2016, respectively. Our institutional sample was matched 1:1 to an American College of Surgeons National Trauma Databank sample using propensity score matching based on age, sex, mechanism of injury, and abdominal Abbreviated Injury Scale score. The primary outcome was time to laparotomy incision. Secondary outcomes included blood transfusion requirement, intensive care unit (ICU) length of stay (LOS), ventilator days, hospital LOS, and in-hospital mortality.

RESULTS

Two hundred forty patients were included (120 institutional, 120 national). Both samples were well balanced, and 83.3% sustained penetrating trauma. There were 84.2% young adults between the ages of 15 and 47, 91.7% were male, 47.5% Black/African American, with a median Injury Severity Score of 14 (interquartile range [IQR], 8-29), Glasgow Coma Scale score of 15 (IQR, 13-15), 71.7% had an systolic blood pressure of >90 mm Hg, and had a shock index of 0.9 (IQR, 0.7-1.1) which did not differ between groups (p > 0.05). Treatment in the EDOR was associated with decreased time to incision (25.5 minutes vs. 40 minutes; p ≤ 0.001), ICU LOS (1 vs. 3.1 days; p < 0.001), transfusion requirement within 24 hours (3 units vs. 5.8 units packed red blood cells; p = 0.025), hospital LOS (5 days vs. 8.5 days, p = 0.014), and ventilator days (1 day vs. 2 days; p ≤ 0.001). There were no significant differences in in-hospital mortality (22.5% vs. 15.0%; p = 0.14) or outcome-free days (4.9 days vs. 4.5 days, p = 0.55).

CONCLUSION

The use of an EDOR is associated with decreased time to hemorrhage control as evidenced by the decreased time to incision, blood transfusion requirement, ICU LOS, hospital LOS, and ventilator days. These findings support DOR for patients sustaining operative abdominal trauma.

LEVEL OF EVIDENCE

Therapeutic/Care Management, Level III.

Interhospital Variations in Resource Use Intensity for In-hospital Injury Deaths: A Retrospective Multicenter Cohort Study

OBJECTIVE

Evaluate interhospital variation in resource use for in-hospital injury deaths.

BACKGROUND

Significant variation in resource use for end-of-life care has been observed in the US for chronic diseases. However, there is an important knowledge gap on end-of-life resource use for trauma patients.

METHODS

We conducted a multicenter, retrospective cohort study of injury deaths following hospitalization in any of the 57 trauma centers in a Canadian trauma system (2013-2016). Resource use intensity was measured using activity-based costing (2016 $CAN) according to time of death (72 h, 3-14 d, ≥14 d). We used multilevel log-linear regression to model resource use and estimated interhospital variation using intraclass correlation coefficients (ICC).

RESULTS

Our study population comprised 2044 injury deaths. Variation in resource use between hospitals was observed for all 3 time frames (ICC = 6.5%, 6.6%, and 5.9% for < 72 h, 3-14 d, and ≥14 d, respectively). Interhospital variation was stronger for allied health services (ICC = 18 to 26%), medical imaging (ICC = 4 to 10%), and the ICU (ICC = 5 to 6%) than other activity centers. We observed stronger interhospital variation for patients < 65 years of age (ICC = 11 to 34%) than those ≥65 (ICC = 5 to 6%) and for traumatic brain injury (ICC = 5 to 13%) than other injuries (ICC = 1 to 8%).

CONCLUSIONS

We observed variation in resource use intensity for injury deaths across trauma centers. Strongest variation was observed for younger patients and those with traumatic brain injury. Results may reflect variation in level of care decisions and the incidence of withdrawal of life-sustaining therapies.

Adherence to Clinical Practice Guideline Recommendations on Low-Value Injury Care: A Multicenter Retrospective Cohort Study

OBJECTIVES

Low-value clinical practices have been identified as one of the most important areas of excess healthcare spending. Nevertheless, there is a knowledge gap on the scale of this problem in injury care. We aimed to identify clinical practice guideline (CPG) recommendations pertaining to low-value injury care, estimate how frequently they are used in practice, and evaluate interhospital variations in their use.

METHODS

We identified low-value clinical practices from internationally recognized CPGs. We conducted a retrospective cohort study using data from a Canadian trauma system (2014-2019) to calculate frequencies and assess interhospital variations.

RESULTS

We identified 29 low-value practices. Fourteen could be measured using trauma registry data. The 3 low-value clinical practices with the highest absolute and relative frequencies were computed tomography (CT) in adults with minor head injury (n = 5591, 24%), cervical spine CT (n = 2742, 31%), and whole-body CT in minor or single-system trauma (n = 530, 32%). We observed high interhospital variation for decompressive craniectomy in diffuse traumatic brain injury. Frequencies and interhospital variations were low for magnetic resonance imaging, intracranial pressure monitoring, inferior vena cava filter use, and surgical management of blunt abdominal injuries.

CONCLUSIONS

We observed evidence of poor adherence to CPG recommendations on low-value CT imaging and high practice variation for decompressive craniectomy. Results suggest that adherence to recommendations for the 10 other low-value practices is high. These data can be used to advance the research agenda on low-value injury care and inform the development of interventions targeting reductions in healthcare overuse in this population.

Use of angioembolization in pediatric polytrauma patients: WITH BLUNT SPLENIC INJURYAngioembolization in Pediatric Blunt Splenic Injury

BACKGROUND/PURPOSE

We sought to analyze the use of angioembolization (AE) after pediatric splenic injuries at adult and pediatric trauma centers (ATCs/PTCs).

METHODS

The National Trauma Data Bank (2010-2015) was queried for patients (<18 years) who experienced blunt splenic trauma. Multivariate logistic regression was used to determine the association of AE with splenectomy. Propensity score matching was used to explore the relationship between trauma center designation and AE utilization.

RESULTS

14,027 encounters met inclusion criteria. 514 (3.7%) patients underwent AE. When compared to PTCs, patients were older, had a higher ISS, and more often presented in shock at ATCs (p<0.001 for all). Regression models demonstrated no difference in mortality between cohorts. Odds of splenectomy were lower for patients undergoing AE (OR 0.16 [CI: 0.08-0.31]), however this effect was mostly driven by utilization at ATCs. Using a 1:1 propensity score matching model, patients treated at ATCs were 4 times more likely to undergo AE and 7 times more likely to require a splenectomy compared to PTCs (p<0.001). Over 6 years, PTCs performed only 27 splenectomies and 23 AEs (1.1% and 0.9%, respectively).

CONCLUSIONS

AE was associated with improved splenic salvage at ATCs in select patients but appeared overutilized when compared to outcomes at PTCs. PTCs accomplished a higher splenic salvage rate with a lower AE utilization.

LEVEL OF EVIDENCE

III - Retrospective cohort study.

Substance use and suicide outcomes among self-injured trauma patients

BACKGROUND

Research indicates alcohol (AUD) or substance (SUD) use disorders and acute alcohol or drug use serve as risk factors for suicidal behaviors and death both distally and proximally to a suicidal event. However, limited research has investigated these relationships among medically serious suicide attempters at the time of injury without relying on cohorts of substance users only or by examining suicide decedent characteristics.

METHODS

Data were collected from the National Trauma Data Bank (NTDB) for 2017. The sample comprised patients who engaged in suicidal and self-injurious acts that were medically serious enough to require trauma admission and were tested for alcohol (N = 9,196) or drug (N = 8,121) exposure upon admission. Logistic regression determined relationships between acute alcohol/substance use, presence of AUDs and SUDs and suicide mortality risk, while linear regression evaluated substance conditions and injury severity and length of stay (LOS).

RESULTS

AUDs (OR = 0.59[0.42-0.83]) and SUDs (OR = 0.66[0.48-0.90]) had reduced odds of death but increased LOS (β = 1.7, p < .001; β = 0.82, p = .024). Blood alcohol concentration (BAC) was positively associated with reduced odds of death (OR = 0.20[0.06-0.61]), injury severity (β = -5.3, p < .001), and LOS (β = -7.5, p < .001). Presence of cocaine (β = -0.80, p = .044) and opioids (β = -1.4, p < .001) were associated lower injury severity, while MDMA (β = 3.6, p = .016) and methamphetamine (β = 1.5, p = .025) were associated with increased injury severity.

CONCLUSIONS

While higher BAC may be associated with lower odds of mortality during a single high-risk suicide event, substance users may be at increased risk for worse outcomes over time. Targeted interventions should be considered to interrupt and develop healthy alternatives for survivors with substance use conditions.

A practical method for dealing with missing Glasgow Coma Scale verbal component scores

OBJECTIVE

The Glasgow Coma Scale (GCS) is used for the assessment of impaired consciousness; however, it is not always possible to test each component, most commonly the verbal component. This affects the derivation of the GCS sum score, which has a role in systems for predicting patient outcome. Imputation of missing scores does not add extra information, but it does allow use of tools for predicting outcome that require complete data. The authors devised a simple and practical tool to employ when verbal component data are missing. They then assessed the tool's utility by application to the GCS-Pupils plus age plus CT findings (GCS-PA CT) prognostic model.

METHODS

The authors inspected data from the International Mission for Prognosis and Analysis of Clinical Trials in Traumatic Brain Injury (IMPACT) cohort to characterize the frequency of missing verbal scores. The authors identified a single verbal score to impute for each eye and motor combined sum (EM) score from distributions of verbal scores in a published database of 54,069 patients. The effectiveness of the imputed verbal score was assessed using a dataset containing information from the IMPACT and Corticosteroid Randomisation After Significant Head Injury (CRASH) databases. The authors compared the performance of the prognostic model using actual verbal scores with the performance using imputed verbal scores and assessed the information yield using Nagelkerke's R2 statistic.

RESULTS

Verbal data were most commonly missing in patients with no eye opening and with a motor score of 4 or less. The "simple" imputation model that was developed performed as well as a more complex model involving distinct combinations of eye and motor scores. The imputation model consisted of the following: EM scores 2-6, add 1; EM score 7, add 2; EM score 8 or 9, add 4; and EM score 10, add 5 to provide the GCS sum score. Modeling without information about the verbal score reduced the R2 from 32.1% to 31.4% and from 34.9% to 34.0% for predictions of death and favorable outcome at 6 months, respectively, compared with using full verbal score information.

CONCLUSIONS

This strategy is particularly valuable for imputation in clinical practice, enabling clinicians to make a rapid and reliable determination of the GCS sum score when the verbal component is not testable. This will support clinical communication and decisions based on estimates of injury severity as well as enable estimation of prognosis. The authors suggest that external validation of their imputation strategy and the performance of the GCS-PA charts should be undertaken in other clinical populations.

Derivation and validation of actionable quality indicators targeting reductions in complications for injury admissions

PURPOSE

Approximately, one out of five patients hospitalized following injury will develop at least one hospital complication, more than three times that observed for general admissions. We currently lack actionable Quality Indicators (QI) targeting specific complications in this population. We aimed to derive and validate QI targeting hospital complications for injury admissions and develop algorithms to identify patient charts to review.

METHODS

We conducted a retrospective cohort study including patients with major trauma admitted to any level I or II adult trauma center an integrated Canadian trauma system (2014-2019). We used the trauma registry to develop five QI targeting deep vein thrombosis/pulmonary embolism (DVT/PE), decubitus ulcers, delirium, pneumonia and urinary tract infection (UTI). We developed algorithms to identify patient charts to revise on consultation with a group of clinical experts.

RESULTS

The study population included 14,592 patients of whom 5.3% developed DVT or PE, 2.7% developed a decubitus ulcer, 8.6% developed delirium, 14.7% developed pneumonia and 7.3% developed UTI. The indicators demonstrated excellent predictive performance (Area Under the Curve 0.81-0.87). We identified 4 hospitals with a higher than average incidence of at least one of the targeted complications. The algorithms identified on average 50 and 20 charts to be reviewed per year for level I and II centers, respectively.

CONCLUSION

In line with initiatives to improve the quality of trauma care, we propose QI targeting reductions in hospital complications for injury admissions and algorithms to generate case lists to facilitate the review of patient charts.

A Leg to Stand on: Trauma Center Designation and Association with Rate of Limb Salvage in Patients Suffering Severe Lower Extremity Injury

BACKGROUND

Mangled extremities are one of the most difficult injuries for trauma surgeons to manage. We compare limb salvage rates for a limb-threatening lower extremity injuries managed at Level I vs Level II trauma centers (TCs).

STUDY DESIGN

We identified all adult patients with a limb-threatening injury who underwent primary amputation or limb salvage (LS) using the American College of Surgeons (ACS) Trauma Quality Improvement Program database at ACS Level I vs II TCs between 2007 and 2017. A limb-threatening injury was defined as an open tibial fracture with concurrent arterial injury (Gustilo type IIIc). Multivariable analysis and propensity score matching were performed to minimize confounding by indication.

RESULTS

There were 712 records for analysis; 391 (54.9%) LS performed and 321 (45.1%) underwent amputation. The rate of LS was statistically higher among patients treated at Level I TCs vs those treated at Level II TCs (47.4% vs 34.8%; p = 0.01). Patients with penetrating injuries (13% vs 9.5%; p = 0.046) and tibial/peroneal artery injury (72.9% vs 50.4%; p < 0.001), as opposed to popliteal artery injury (30.8% vs 58.8%; p < 0.001), were more likely to have LS. The risk-adjusted odds of LS was 3.13 times higher at Level I TCs vs Level II TCs (95% CI, 1.59 to 6.34; p = 0.001). Limb salvage rates were significantly higher at Level I TCs compared with Level II TCs (53.0% vs 34.8%; p = 0.004), even after propensity matching.

CONCLUSIONS

In patients with a mangled extremity, limb salvage rates are 50% higher at Level I TCs compared with Level II TCs, independent of case mix and injury severity.

Development and Validation of a Hospital Indicator of Activity-Based Costs for Injury Admissions

OBJECTIVES

To develop a hospital indicator of resource use for injury admissions.

METHODS

We focused on resource use for acute injury care and therefore adopted a hospital perspective. We included patients ≥16 years old with an Injury Severity Score >9 admitted to any of the 57 trauma centers of an inclusive Canadian trauma system from 2014 to 2018. We extracted data from the trauma registry and hospital financial reports and estimated resource use with activity-based costing. We developed risk-adjustment models by trauma center designation level (I/II and III/IV) for the whole sample, traumatic brain injuries, thoraco-abdominal injuries, orthopedic injuries, and patients ≥65 years old. Candidate variables were selected using bootstrap resampling. We performed benchmarking by comparing the adjusted mean cost in each center, obtained using shrinkage estimates, to the provincial mean.

RESULTS

We included 38 713 patients. The models explained between 12% and 36% (optimism-corrected r²) of the variation in resource use. In the whole sample and in all subgroups, we identified centers with higher- or lower-than-expected resource use across level I/II and III/IV centers.

CONCLUSIONS

We propose an algorithm to produce the indicator using data routinely collected in trauma registries to prompt targeted exploration of potential areas for improvement in resource use for injury admissions. The r² of our models suggest that between 64% and 88% of the variation in resource use for injury care is dictated by factors other than patient baseline risk.

The Whole is Greater Than the Sum of its Parts: GCS Versus GCS-Motor for Triage in Geriatric Trauma

BACKGROUND

Trauma field triage matches injured patients to the appropriate level of care. Prior work suggests the Glasgow Coma Scale motor (GCSm) is as accurate as the total GCS (GCSt) and easier to use. However, older patients present with higher GCS for a given injury, and as such, it is unclear if this substitution is advisable. Our objective was to compare the GCS deficit patterns between geriatric and adult patients presenting with severe traumatic brain injury (TBI), as well as the diagnostic performance of the GCSm versus GCSt within the field triage criteria in these populations.

MATERIALS AND METHODS

We conducted a retrospective, observational cohort study of patients ≥16 y in the National Trauma Data Bank 2007-2015. GCS deficit patterns were compared between adults (16-65) and geriatric patients (>65). Measures of diagnostic performance of GCSt≤13 versus GCSm≤5 criteria to predict trauma center need (TCN) were compared.

RESULTS

In total, 4,480,185 patients were analyzed (28% geriatric). Geriatric patients more frequently presented with non-motor-only deficits than adults (16.4% versus 12.4%, P < 0.001), and these patients demonstrated higher severe TBI (40.3% versus 36.7%, P < 0.001) and craniotomy (5.8% versus 5.1%, P < 0.001) rates. GCSt was more sensitive and accurate in predicting TCN for geriatric patients and had lower rates of undertriage as compared to GCSm.

CONCLUSIONS

Geriatric patients more frequently present with non-motor-only deficits after injury, and this is associated with severe head injury. Substitution of GCSm for GCSt would exacerbate undertriage in geriatric patients and, thus, the total GCS should be maintained for field triage in geriatric patients.

Neonatal NIRS monitoring: recommendations for data capture and review of analytics

Brain injury is one of the most consequential problems facing neonates, with many preterm and term infants at risk for cerebral hypoxia and ischemia. To develop effective neuroprotective strategies, the mechanistic basis for brain injury must be understood. The fragile state of neonates presents unique research challenges; invasive measures of cerebral blood flow and oxygenation assessment exceed tolerable risk profiles. Near-infrared spectroscopy (NIRS) can safely and non-invasively estimate cerebral oxygenation, a correlate of cerebral perfusion, offering insight into brain injury-related mechanisms. Unfortunately, lack of standardization in device application, recording methods, and error/artifact correction have left the field fractured. In this article, we provide a framework for neonatal NIRS research. Our goal is to provide a rational basis for NIRS data capture and processing that may result in better comparability between studies. It is also intended to serve as a primer for new NIRS researchers and assist with investigation initiation.

Inter-hospital variation in surgical intensity for trauma admissions: A multicentre cohort study

BACKGROUND

Guidelines for injury care are increasingly moving away from surgical management towards less invasive procedures but there is a knowledge gap on how these recommendations are influencing practice. We aimed to assess inter-hospital variation in surgical intensity for injury admissions and evaluate the correlation between hospital surgical intensity and mortality/complications.

METHODS

We included adults admitted for major trauma between 2006 and 2016 in a Canadian provincial trauma system. Analyses were stratified for orthopaedic (n = 16 887), neurological (n = 12 888) and torso injuries (n = 9816). Surgical intensity was quantified with the number of surgical procedures <72 hours. Inter-hospital variation was assessed with the intra-class correlation coefficient (ICC). We assessed the correlation between the risk-adjusted mean number of surgical procedures and risk-adjusted incidence of mortality and complications using Pearson correlation coefficients (r).

RESULTS

Moderate inter-hospital variation was observed for orthopaedic surgery (ICC = 14.0%) whereas variation was low for torso surgery (ICC = 2.7%) and neurosurgery (ICC = 0.8%). Surgical intensity was negatively correlated with hospital mortality for torso injury (r = -.32, P = .02) and neurotrauma (r = -.65, P = .08). A strong positive correlation was observed with hospital complications for orthopaedic injuries (r = .36, P = .006) whereas the opposite was observed for neurotrauma (r = -.71, P = .05).

CONCLUSIONS

Results should be interpreted with caution as they may be a result of residual confounding. However, they may suggest that there are opportunities for quality improvement in surgical care for injury admissions, particularly for orthopaedic injuries. Moving forward, we should aim to prospectively evaluate adherence to guidelines on non-operative management and their impact on mortality and morbidity.

Life-saving interventions in pediatric trauma: A National Trauma Data Bank experience

BACKGROUND

Emergent procedures are infrequent in pediatric trauma. We sought to determine the frequency and efficacy of life-saving interventions (LSI) performed for pediatric trauma patients within the first hour of care at a trauma center.

METHODS

The National Trauma Data Bank (2010-2014) was queried for patients 19 years or younger who underwent LSIs within 1 hour of arrival to the emergency department. Life-saving interventions included emergency department thoracotomy (EDT) and emergent airway procedures (EAP). Multivariable logistic regression was used to evaluate the influence of patient and hospital characteristics on mortality.

RESULTS

Of 725,284 recorded traumatic encounters, only 1,488 (0.2%) pediatric patients underwent at least one of the defined LSI during the 5-year study period (EDT, 1,323; EAP, 187). Most patients (85.6%) were 15 years or older. Mortality was high but varied by procedure type (EDT, 64.3%; EAP, 28.3%). Mortality for patients younger than 1 year undergoing EDT was 100%, decreasing to 62.6% in patients aged 15 years to 19 years. For EAP, mortality ranged from 66.7% for infants to 27.2% in 15-year-old to 19-year-old patients. Lower Glasgow Coma Scale score, higher Injury Severity Score, presence of shock, and a blunt mechanism of injury were independently associated with mortality in the EDT cohort. On average, trauma centers in this study performed approximately one LSI per year, with only 13.8% of cases occurring at a verified pediatric trauma center.

CONCLUSION

Life-saving interventions in the pediatric trauma population are uncommon and outcomes variable. Novel solutions to keep proficient at such interventions should be sought, especially for younger children. Guidelines to improve identification of appropriate candidates for LSI are critical given their rare occurrence.

LEVEL OF EVIDENCE

Retrospective cohort study, III.

Defining the role of angioembolization in pediatric isolated blunt solid organ injury

PURPOSE

To determine the incidence and outcomes of angiography in pediatric patients with blunt solid organ injury (SOI).

METHODS

The National Trauma Data Bank (2010-2014) was queried for patients ≤19 years who experienced isolated blunt SOI. Multivariate logistic regression was used to evaluate characteristics associated with radiological and surgical intervention.

RESULTS

Patients with isolated blunt injuries to the spleen (n = 7542), liver (n = 4549), and kidney (n = 2640) were identified. Use of angiography increased yearly from 1.6% to 3.1% of cases (p = 0.001) and was associated with older age (OR 2.61 [CI: 1.94-3.50], p < 0.001) and grade III or higher injury (OR 4.63 [CI: 3.11-6.90], p < 0.001). Odds of angiography were 4.9 times higher at adult trauma centers (TCs) than pediatric TCs overall, and almost 9 times higher for isolated splenic trauma (p < 0.001 for each). There was no improvement in splenic salvage after angiography for high grade injuries (3.5% vs. 4.8%, p = NS). Only 1.8% of cases began within 30 min of arrival (median time = 3.6 h).

CONCLUSION

Variability exists in the utilization of angiography in pediatric blunt SOI between adult and pediatric TCs, with no improvement in splenic salvage.

LEVEL OF EVIDENCE

Level III - Treatment study.

Establishing a Multicentre Trauma Registry in India: An Evaluation of Data Completeness

BACKGROUND

The completeness of a trauma registry's data is essential for its valid use. This study aimed to evaluate the extent of missing data in a new multicentre trauma registry in India and to assess the association between data completeness and potential predictors of missing data, particularly mortality.

METHODS

The proportion of missing data for variables among all adults was determined from data collected from 19 April 2016 to 30 April 2017. In-hospital physiological data were defined as missing if any of initial systolic blood pressure, heart rate, respiratory rate, or Glasgow Coma Scale were missing. Univariable logistic regression and multivariable logistic regression, using manual stepwise selection, were used to investigate the association between mortality (and other potential predictors) and missing physiological data.

RESULTS

Data on the 4466 trauma patients in the registry were analysed. Out of 59 variables, most (n = 51; 86.4%) were missing less than 20% of observations. There were 808 (18.1%) patients missing at least one of the first in-hospital physiological observations. Hospital death was associated with missing in-hospital physiological data (adjusted OR 1.4; 95% CI 1.02-2.01; p = 0.04). Other significant associations with missing data were: patient arrival time out of hours, hospital of care, 'other' place of injury, and specific injury mechanisms. Assault/homicide injury intent and occurrence of chest X-ray were associated with not missing any of first in-hospital physiological variables.

CONCLUSION

Most variables were well collected. Hospital death, a proxy for more severe injury, was associated with missing first in-hospital physiological observations. This remains an important limitation for trauma registries.

Patient-level resource use for injury admissions in Canada: A multicentre retrospective cohort study

BACKGROUND

Variations in adjusted costs have been observed among trauma centres in the United States but patient outcomes were not better in centres with higher costs. Attempts to improve injury care efficiency are hampered by insufficient patient-level information on resource use and on the drivers of resource use intensity.

OBJECTIVES

To estimate patient-level resource use for injury admissions, identify determinants of resource use intensity, and evaluate inter-hospital variations in resource use.

METHODS

We conducted a retrospective cohort study including ≥16-year-olds admitted to adult trauma centres in a mature, inclusive Canadian trauma system between 2014 and 2016. We extracted data from the trauma registry and hospital financial reports. We estimated resource use with activity-based costs, identified determinants of resource use intensity using a multilevel linear model and assessed the relative importance of each determinant with Cohen's f². We evaluated inter-provider variations with intraclass correlation coefficients (ICC) and 95% confidence intervals.

RESULTS

We included 32,411 patients. Median costs per admission were $4857 (Quartiles 1 and 3 2961-8448). The most important contributors to total resource use were the medical ward (57%), followed by the operating room (OR; 23%) and the intensive care unit (13%). The strongest determinant of resource use intensity was discharge destination (Cohen's f² = 7%). The most resource intense patient group was spinal cord injuries with $11,193 (7115-17,606) per admission. While resource use increased with increasing age for the medical ward, it decreased with increasing age for the OR. Resource use was 18% higher in level I centres compared to level IV centres and we observed significant variations in resource use across centres (ICC = 5% [4-6]), particularly for the OR (28% [20-40]).

CONCLUSIONS

Resource use for acute injury care in Quebec is not solely due to the clinical status of patients. We identified determinants of resource use that can be used to establish evidence-based resource allocations and improve injury care efficiency. The method we developed for estimating patient-level, in-hospital resource use for injury admissions and identifying related determinants could be reproduced using local trauma registry data and our unit costs or unit costs specific to each setting.

The value of failure to rescue in determining hospital quality for pediatric trauma

BACKGROUND

In adult trauma patients, high- and low-mortality trauma hospitals have similar rates of major complications but differ based on failure to rescue (mortality following a major complication), which has become a marker of hospital quality. The aim of this study is to examine whether failure to rescue is also an appropriate hospital quality indicator in pediatric trauma.

METHODS

Children younger than 15 years were identified in the 2007 to 2014 National Trauma Databank research data sets. Hospitals were classified as a high, average or low mortality based on risk-adjusted observed-to-expected in-hospital mortality ratios using the modified Trauma Mortality Probability Model. Regression modeling was used to explore the impact of hospital quality ranking on the incidence of major complications and failure to rescue.

RESULTS

Of 125,057 children, 31,600 were treated at low-mortality outlier hospitals, and 7,014 at high-mortality outlier hospitals. Low-mortality hospitals had a lower rate of major complications compared with high-mortality hospitals (0.5% [low] vs. 0.8% [high]; adjusted odds ratio [OR], 0.71; 95% confidence interval [CI], 0.61-0.83; p < 0.01) and a lower failure-to-rescue rate (17.6% [low] vs. 24.1% [high]; adjusted OR, 0.53 [high; 95% CI 0.34-0.83; p < 0.01]). When patients who died within 48 hours were excluded, low-mortality hospitals had a lower complication rate (OR, 0.81; 95% CI, 0.68, 0.96; p = 0.02), but similar failure-to-rescue rate compared to high-mortality hospitals. There was no correlation between trauma verification level and hospital mortality status based on the model.

CONCLUSION

For pediatric trauma patients, mortality is more strongly associated with major complication rate than with failure to rescue. Thus, failure to rescue does not appear to be the key driver of hospital quality in this population as it does in the adult trauma population.

LEVEL OF EVIDENCE

Prognostic and epidemiological, level III.

Individual and School Correlates of Adolescent Leisure Time Physical Activity in Quebec, Canada

Background: Leisure time physical activity (LTPA) correlates have been mostly studied in relation to adolescents’ home neighbourhoods, but not so much in relation to the environment of their schools’ neighbourhoods. We sought to investigate how objective environmental measures of the schools’ vicinity are related to adolescents’ self-reported LTPA. Methods: Individual data from the Quebec High School Students Health Survey (QHSSHS) were matched with schools’ socioeconomic indicators, as well as geographic information system-based indicators of their built environments. Self-reported levels of LTPA during the school year were assessed according to intensity, frequency and index of energy expenditure. Associations per gender between covariates and LTPA were estimated using ordinal multilevel regression with multiple imputations. Results: Boys (21% of which were highly active) were more active than girls (16% of which were highly active) (p ≤ 0.01). The incremental variance between schools explained by the contextual variables in the final models was higher among girls (7.8%) than boys (2.8%). The number of parks or green spaces within 750 m around their schools was positively associated with student LTPA in both genders. Conclusions: The promotion of parks around schools seems to be an avenue to be strengthened.

Hemoglobin thresholds and red blood cell transfusion in adult patients with moderate or severe traumatic brain injuries: A retrospective cohort study

PURPOSE

We aimed to evaluate the association between transfusion practices and clinical outcomes in patients with traumatic brain injury.

MATERIAL AND METHODS

We conducted a retrospective cohort study of adult patients with moderate or severe traumatic brain injury admitted to the intensive care unit (ICU) of a level I trauma center between 2009 and 2013. The associations between hemoglobin (Hb) level, red blood cell (RBC) transfusion and clinical outcomes were estimated using robust Poisson models and proportional hazard models with time-dependent variables, adjusted for confounders.

RESULTS

We included 215 patients. Sixty-six patients (30.7%) were transfused during ICU stay. The median pre-transfusion Hb among transfused patients was 81g/L (IQR 67-100), while median nadir Hb among non-transfused patients was 110g/L (IQR 93-123). Poor outcomes were significantly more frequent in patients who were transfused (mortality risk ratio [RR]: 2.15 [95% CI 1.37-3.38] and hazard ratio: 3.06 [95% CI 1.57-5.97]; neurological complications RR: 3.40 [95% CI 1.35-8.56]; trauma complications RR: 1.65 [95% CI 1.31-2.08]; ICU length of stay geometric mean ratio: 1.42 [95% CI 1.06-1.92]).

CONCLUSIONS

During ICU stay, transfused patients tended to have lower Hb levels and worse outcomes than patients who did not receive RBCs, after adjustment for confounders.

Hospital and Intensive Care Unit Length of Stay for Injury Admissions: A Pan-Canadian Cohort Study

OBJECTIVE

To assess the variation in hospital and intensive care unit (ICU) length of stay (LOS) for injury admissions across Canadian provinces and to evaluate the relative contribution of patient case mix and treatment-related factors (intensity of care, complications, and discharge delays) to explaining observed variations.

BACKGROUND

Identifying unjustified interprovider variations in resource use and the determinants of such variations is an important step towards optimizing health care.

METHODS

We conducted a multicenter, retrospective cohort study on admissions for major trauma (injury severity score >12) to level I and II trauma centers across Canada (2006-2012). We used data from the Canadian National Trauma Registry linked to hospital discharge data to compare risk-adjusted hospital and ICU LOS across provinces.

RESULTS

Risk-adjusted hospital LOS was shortest in Ontario (10.0 days) and longest in Newfoundland and Labrador (16.1 days; P < 0.001). Risk-adjusted ICU LOS was shortest in Québec (4.4 days) and longest in Alberta (6.1 days; P < 0.001). Patient case-mix explained 32% and 8% of interhospital variations in hospital and ICU LOS, respectively, whereas treatment-related factors explained 63% and 22%.

CONCLUSIONS

We observed significant variation in risk-adjusted hospital and ICU LOS across trauma systems in Canada. Provider ranks on hospital LOS were not related to those observed for ICU LOS. Treatment-related factors explained more interhospital variation in LOS than patient case-mix. Results suggest that interventions targeting reductions in low-value procedures, prevention of adverse events, and better discharge planning may be most effective for optimizing LOS for injury admissions.

Perceived social risk in medical decision-making for physical child abuse: a mixed-methods study

Background

The medical literature reports differential decision-making for children with suspected physical abuse based on race and socioeconomic status. Differential evaluation may be related to differences of risk indicators in these populations or differences in physicians’ perceptions of abuse risk. Our objective was to understand the contribution of the child’s social ecology to child abuse pediatricians’ perception of abuse risk and to test whether risk perception influences diagnostic decision-making.

Methods

Thirty-two child abuse pediatrician participants prospectively contributed 746 consultations from for children referred for physical abuse evaluation (2009–2013). Participants entered consultations to a web-based interface. Participants noted their perception of child race, family SES, abuse diagnosis. Participants rated their perception of social risk for abuse and diagnostic certainty on a 1–100 scale. Consultations (n = 730) meeting inclusion criteria were qualitatively analyzed for social risk indicators, social and non-social cues. Using a linear mixed-effects model, we examined the associations of social risk indicators with participant social risk perception. We reversed social risk indicators in 102 cases whilst leaving all injury mechanism and medical information unchanged. Participants reviewed these reversed cases and recorded their social risk perception, diagnosis and diagnostic certainty.

Results

After adjustment for physician characteristics and social risk indicators, social risk perception was highest in the poorest non-minority families (24.9 points, 95%CI: 19.2, 30.6) and minority families (17.9 points, 95%CI, 12.8, 23.0). Diagnostic certainty and perceived social risk were associated: certainty increased as social risk perception increased (Spearman correlation 0.21, p < 0.001) in probable abuse cases; certainty decreased as risk perception increased (Spearman correlation (−)0.19, p = 0.003) in probable not abuse cases. Diagnostic decisions changed in 40% of cases when social risk indicators were reversed.

Conclusions

CAP risk perception that poverty is associated with higher abuse risk may explain documented race and class disparities in the medical evaluation and diagnosis of suspected child physical abuse. Social risk perception may act by influencing CAP certainty in their diagnosis.

Imputation strategies in the trauma registration

BACKGROUND

Trauma databases often contain relatively high proportions of missing physiologic values. Multiple imputation (MI) could be a possible adequate solution for the missing values. This study aimed to demonstrate the influence of more simplified imputation models on standardized W statistic (Ws) (number of excess survivors per hundred patients that would be achieved if the study center treated identically the same case mix as the reference population).

METHODS

Data from three trauma care networks in the Netherlands were used to investigate local differences in missing data. Five different imputation models (MI 1 to 5) were created based on literature and expert opinion. A sixth database was created using maximal single imputation and a seventh database with only complete case analysis (CCA). The Ws values were calculated for the three regions separately.

RESULTS

A total of 8,853, 24,487, and 8,599 observations were examined in region 1, region 2, and region 3, respectively. The Ws in region 1 ranged from -0.48 (95% confidence interval [CI], -1.71 to 0.80) for CCA to 0.53 (95% CI, -0.19 to 1.26) for MI 4 and a range of 0.40 (95% CI, -0.91 to 0.10) for CCA to -0.32 (-0.69, 0.04) for MI 1 and MI 4 was found in region 2. The Ws for region 3 ranged from -0.19 (-0.83 to 0.45) in all MI data sets to -0.12 (-0.76 to 0.52) in the CCA data set. Although there were no significant differences between the Ws of the imputation data sets and the CCA analysis, large differences were found in the region with the most missing values.

CONCLUSION

Different imputation strategies did influence Ws values. Supplementary variables showed no additional value for the imputation process and a more simplified imputation model could be used to adequately impute missing data.

LEVEL OF EVIDENCE

Prognostic, level II.

External validation of the Air Medical Prehospital Triage score for identifying trauma patients likely to benefit from scene helicopter transport

BACKGROUND

The Air Medical Prehospital Triage (AMPT) score was developed to identify injured patients who may benefit from scene helicopter emergency medical services (HEMS) transport. External validation using a different data set is essential to ensure reliable performance. The study objective was to validate the effectiveness of the AMPT score to identify patients with a survival benefit from HEMS using the Pennsylvania Trauma Outcomes Study registry.

METHODS

Patients 16 years or older undergoing scene HEMS or ground EMS (GEMS) transport in the Pennsylvania Trauma Outcomes Study registry 2000-2013 were included. Patients with 2 or higher AMPT score points were triaged to HEMS, while those with less than 2 points were triaged to GEMS. Multilevel Poisson regression determined the association of survival with actual transport mode across AMPT score triage assignments, adjusting for demographics, mechanism, vital signs, interventions, and injury severity. Successful validation was defined as no survival benefit for actual HEMS transport in patients triaged to GEMS by the AMPT score, with a survival benefit for actual HEMS transport in patients triaged to HEMS by the AMPT score. Subgroup analyses were performed in patients treated by advanced life support providers and patients with transport times longer than 10 minutes.

RESULTS

There were 222,827 patients included. For patients triaged to GEMS by the AMPT score, actual transport mode was not associated with survival (adjusted relative risk, 1.004; 95% confidence interval, 0.999-1.009; p = 0.08). For patients triaged to HEMS by the AMPT score, actual HEMS transport was associated with a 6.7% increase in the relative probability of survival (adjusted relative risk, 1.067; 95% confidence interval, 1.040-1.083, p < 0.001). Similar results were seen in all subgroups.

CONCLUSIONS

This study is the first to externally validate the AMPT score, demonstrating the ability of this tool to reliably identify trauma patients most likely to benefit from HEMS transport. The AMPT score should be considered when protocols for HEMS scene transport are developed and reviewed.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level III; therapeutic/care management study, level IV.

Not all prehospital time is equal: Influence of scene time on mortality

BACKGROUND

Trauma is time sensitive, and minimizing prehospital (PH) time is appealing. However, most studies have not linked increasing PH time with worse outcomes because raw PH times are highly variable. It is unclear whether specific PH time patterns affect outcomes. Our objective was to evaluate the association of PH time interval distribution with mortality.

METHODS

Patients transported by emergency medical services in the Pennsylvania trauma registry from 2000 to 2013 with a total PH time (TPT) of 20 minutes or longer were included. TPT was divided into three PH time intervals: response, scene, and transport time. The number of minutes in each PH time interval was divided by TPT to determine the relative proportion each interval contributed to TPT. A prolonged interval was defined as any one PH interval contributing equal to or greater than 50% of TPT. Patients were classified by prolonged PH interval or no prolonged PH interval (all intervals < 50% of TPT). Patients were matched for TPT, and conditional logistic regression determined the association of mortality with PH time pattern, controlling for confounders. PH interventions were explored as potential mediators, and PH triage criteria used identify patients with time-sensitive injuries.

RESULTS

There were 164,471 patients included. Patients with prolonged scene time had increased odds of mortality (odds ratio, 1.21; 95% confidence interval, 1.02-1.44; p = 0.03). Prolonged response, transport, and no prolonged interval were not associated with mortality. When adjusting for mediators including extrication and PH intubation, prolonged scene time was no longer associated with mortality (odds ratio, 1.06; 95% confidence interval, 0.90-1.25; p = 0.50). Together, these factors mediated 61% of the effect between prolonged scene time and mortality. Mortality remained associated with prolonged scene time in patients with hypotension, penetrating injury, and flail chest.

CONCLUSION

Prolonged scene time is associated with increased mortality. PH interventions partially mediate this association. Further study should evaluate whether these interventions drive increased mortality because they prolong scene time or by another mechanism, as reducing scene time may be a target for intervention.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III.

Development and Validation of the Air Medical Prehospital Triage Score for Helicopter Transport of Trauma Patients

OBJECTIVE

The aim of this study was to develop and internally validate a triage score that can identify trauma patients at the scene who would potentially benefit from helicopter emergency medical services (HEMS).

SUMMARY BACKGROUND DATA

Although survival benefits have been shown at the population level, identification of patients most likely to benefit from HEMS transport is imperative to justify the risks and cost of this intervention.

METHODS

Retrospective cohort study of subjects undergoing scene HEMS or ground emergency medical services (GEMS) in the National Trauma Databank (2007-2012). Data were split into training and validation sets. Subjects were grouped by triage criteria in the training set and regression used to determine which criteria had a survival benefit associated with HEMS. Points were assigned to these criteria to develop the Air Medical Prehospital Triage (AMPT) score. The score was applied in the validation set to determine whether subjects triaged to HEMS had a survival benefit when actually transported by helicopter.

RESULTS

There were 2,086,137 subjects included. Criteria identified for inclusion in the AMPT score included GCS <14, respiratory rate <10 or >29, flail chest, hemo/pneumothorax, paralysis, and multisystem trauma. The optimal cutoff for triage to HEMS was ≥2 points. In subjects triaged to HEMS, actual transport by HEMS was associated with an increased odds of survival (AOR 1.28; 95% confidence interval [CI] 1.21-1.36, P < 0.01). In subjects triaged to GEMS, actual transport mode was not associated with survival (AOR 1.04; 95% CI 0.97-1.11, P = 0.20).

CONCLUSIONS

The AMPT score identifies patients with improved survival following HEMS transport and should be considered in air medical triage protocols.

Factors Associated With Nontransfer in Trauma Patients Meeting American College of Surgeons' Criteria for Transfer at Nontertiary Centers

Importance

Secondary triage from nontertiary centers is vital to trauma system success. It remains unclear what factors are associated with nontransfer among patients who should be considered for transfer to facilities providing higher-level care.

Objective

To identify factors associated with nontransfer among patients meeting American College of Surgeons (ACS) guideline criteria for transfer from nontertiary centers.

Design, Setting, and Participants

A retrospective cohort study was performed using multilevel logistic regression to ascertain factors associated with nontransfer from nontertiary centers, including demographics, injury characteristics, and center resources. With information obtained from the National Trauma Data Bank (January 1, 2007, to December 31, 2012), relative proportion of variance in outcome across centers was determined for patient-level and center-level attributes. In all, 96 528 patients taken to nontertiary centers (levels III, IV, V, and nontrauma centers) that met ACS guideline transfer criteria were eligible for inclusion. Data analysis was performed from March 17, 2016, to May 20, 2016.

Main Outcomes and Measures

The primary outcome was nontransfer from a nontertiary center.

Results

Among 96 528 patients meeting ACS guideline criteria for transfer taken initially to nontertiary centers, 55 611 (57.6%) were male and the median age was 52 years (interquartile range, 28-77 years). Only 19 396 patients (20.1%) underwent transfer. Patient-level factors associated with nontransfer included age older than 65 years (adjusted odds ratio [AOR], 1.70; 95% CI, 1.46-1.98; P < .001), severe chest injury (AOR, 1.63; 95% CI, 1.42-1.89; P < .001), and commercial insurance (vs self-pay: AOR, 1.39; 95% CI, 1.15-1.67; P < .001). Center-level factors associated with nontransfer included larger bed size (>600 vs <200 beds: AOR, 9.22; 95% CI, 7.70-11.05; P < .001), nontrauma center (vs level III centers: AOR, 2.71; 95% CI, 2.44-3.01; P < .001), university affiliation (vs community: AOR, 9.68; 95% CI, 8.03-11.66; P < .001), more trauma surgeons (per surgeon: AOR, 1.08; 95% CI, 1.06-1.09; P < .001), and more neurosurgeons (per surgeon: AOR, 1.25; 95% CI, 1.23-1.28; P < .001). For-profit status was associated with nontransfer at nontrauma centers (AOR, 1.55; 95% CI, 1.39-1.74; P < .001), but not at level III, IV, and V trauma centers. Overall, patient-level factors accounted for 36% and center-level factors accounted for 58% of the variation in transfer practices. Patient-level factors accounted for more variation at level III, IV, and V trauma centers (44%), but less variation at nontrauma centers (13%).

Conclusions and Relevance

Only 1 in 5 patients meeting ACS transfer criteria underwent transfer. Factors associated with nontransfer may be useful for trauma system stakeholders to target education and outreach to guide development of more inclusive trauma systems. Further study is necessary to critically evaluate whether these ACS criteria identify patients who require transfer.

The association of patient and trauma characteristics with the health-related quality of life in a Dutch trauma population

Background

It is suggested in literature to use the Health Related Quality of Life (HRQoL) as an outcome indicator for evaluating trauma centre performances. In order to predict HRQoL, characteristics that could be of influence on a predictive model should be identified. This study identifies patient and injury characteristics associated with the HRQoL in a general trauma population.

Methods

Retrospective study of trauma patients admitted from 1st January 2007 through 31th December 2012. Patients were aged ≥18 years and discharged alive from the level I trauma centre. A combined health survey (SF-36 and EQ-5D) was sent to all traceable patients. The subdomain outcomes and EQ-5D index value (EQ-5Di) were compared with the reference population. A linear regression analysis was performed to identify parameters associated parameters with the HRQoL outcome.

Results

A total of 1870 patients were included for analyses. Compared to the eligible population, included patients were significantly older, more severely injured, more often admitted in the ICU and had a longer admission duration.

The SF-36 and EQ-5Di were significantly lower compared to the Dutch reference population.

The variables age, Injury Severity Score, hospital length of stay, ICU length of stay, Revised Trauma Score, probability of survival, and severe injury to the head and extremities were associated with the HRQoL in the majority of the subdomains.

Discussion

In order to use HRQoL as an indicator for trauma centre performances, there should be a consensus of the ideal timing for the measurement of HRQoL post-injury and the appropriate HRQoL instrument. Furthermore, standardised HRQoL outcomes must be developed.

Conclusion

This study revealed eight factors (described above) which could be used to predict the HRQoL in trauma patients.

Impact of trauma centre designation level on outcomes following hemorrhagic shock: a multicentre cohort study

BACKGROUND

Hemorrhagic shock is responsible for 45% of injury fatalities in North America, and 50% of these occur within 2 h of injury. There is currently a lack of evidence regarding the trajectories of patients in hemorrhagic shock and the potential benefit of level I/II care for these patients. We aimed to compare mortality across trauma centre designation levels for patients in hemorrhagic shock. Secondary objectives were to compare surgical delays, complications and hospital length of stay (LOS).

METHODS

We performed a retrospective cohort study based on a Canadian inclusive trauma system (1999-2012), including adults with systolic blood pressure (SBP) < 90 mm Hg on arrival who required urgent surgical care (< 6 h). Logistic regression was used to examine the influence of trauma centre designation level on risk-adjusted surgical delays, mortality and complications. Linear regression was used to examine LOS.

RESULTS

Compared with level I centres, adjusted odds ratios (and 95% confidence intervals [CI]) of mortality for level III and IV centres were 1.71 (1.03-2.85) and 2.25 (1.08-4.73), respectively. Surgical delays did not vary across designation levels, but mean LOS and complications were lower in level II-IV centres than level I centres.

CONCLUSION

Level I/II centres may offer a survival advantage over level III/IV centres for patients requiring emergency intervention for hemorrhagic shock. Further research with larger sample sizes is required to confirm these results and to identify optimal transport time thresholds for bypassing level III/IV centres in favour of level I/II centres.

Transfusion of red blood cells in patients with traumatic brain injuries admitted to Canadian trauma health centres: a multicentre cohort study

BACKGROUND

Optimisation of healthcare practices in patients sustaining a traumatic brain injury is of major concern given the high incidence of death and long-term disabilities. Considering the brain's susceptibility to ischaemia, strategies to optimise oxygenation to brain are needed. While red blood cell (RBC) transfusion is one such strategy, specific RBC strategies are debated. We aimed to evaluate RBC transfusion frequency, determinants of transfusions and associated clinical outcomes.

METHODS

We conducted a retrospective multicentre cohort study using data from the National Trauma Registry of Canada. Patients admitted with moderate or severe traumatic brain injury to participating hospitals between April 2005 and March 2013 were eligible. Patient information on blood products, comorbidities, interventions and complications from the Discharge Abstract Database were linked to the National Trauma Registry data. Relative weights analyses evaluated the contribution of each determinant. We conducted multivariate robust Poisson regression to evaluate the association between potential determinants, mortality, complications, hospital-to-home discharge and RBC transfusion. We also used proportional hazard models to evaluate length of stay for time to discharge from ICU and hospital.

RESULTS

Among the 7062 patients with traumatic brain injury, 1991 patients received at least one RBC transfusion during their hospital stay. Female sex, anaemia, coagulopathy, sepsis, bleeding, hypovolemic shock, other comorbid illnesses, serious extracerebral trauma injuries were all significantly associated with RBC transfusion. Serious extracerebral injuries altogether explained 61% of the observed variation in RBC transfusion. Mortality (risk ratio (RR) 1.23 (95% CI 1.13 to 1.33)), trauma complications (RR 1.38 (95% CI 1.32 to 1.44)) and discharge elsewhere than home (RR 1.88 (95% CI 1.75 to 2.04)) were increased in patients who received RBC transfusion. Discharge from ICU and hospital were also delayed in transfused patients.

CONCLUSIONS

RBC transfusion is common in patients with traumatic brain injury and associated with unfavourable outcomes. Trauma severity is an important determinant of RBC transfusion. Prospective studies are needed to further evaluate optimal transfusion strategies in traumatic brain injury.

Mortality prediction models in the general trauma population: A systematic review

BACKGROUND

Trauma is the leading cause of death in individuals younger than 40 years. There are many different models for predicting patient outcome following trauma. To our knowledge, no comprehensive review has been performed on prognostic models for the general trauma population. Therefore, this review aimed to describe (1) existing mortality prediction models for the general trauma population, (2) the methodological quality and (3) which variables are most relevant for the model prediction of mortality in the general trauma population.

METHODS

An online search was conducted in June 2015 using Embase, Medline, Web of Science, Cinahl, Cochrane, Google Scholar and PubMed. Relevant English peer-reviewed articles that developed, validated or updated mortality prediction models in a general trauma population were included.

RESULTS

A total of 90 articles were included. The cohort sizes ranged from 100 to 1,115,389 patients, with overall mortality rates that ranged from 0.6% to 35%. The Trauma and Injury Severity Score (TRISS) was the most commonly used model. A total of 258 models were described in the articles, of which only 103 models (40%) were externally validated. Cases with missing values were often excluded and discrimination of the different prediction models ranged widely (AUROC between 0.59 and 0.98). The predictors were often included as dichotomized or categorical variables, while continuous variables showed better performance.

CONCLUSION

Researchers are still searching for a better mortality prediction model in the general trauma population. Models should 1) be developed and/or validated using an adequate sample size with sufficient events per predictor variable, 2) use multiple imputation models to address missing values, 3) use the continuous variant of the predictor if available and 4) incorporate all different types of readily available predictors (i.e., physiological variables, anatomical variables, injury cause/mechanism, and demographic variables). Furthermore, while mortality rates are decreasing, it is important to develop models that predict physical, cognitive status, or quality of life to measure quality of care.

Hospital length of stay following admission for traumatic brain injury in a Canadian integrated trauma system: A retrospective multicenter cohort study

BACKGROUND

Traumatic brain injury (TBI) is the leading cause of disability in children and young adults and costs CAD$3 billion annually in Canada. Stakeholders have expressed the urgent need to obtain information on resource use for TBI to improve the quality and efficiency of acute care in this patient population. We aimed to assess the components and determinants of hospital and ICU LOS for TBI admissions.

METHODS

We performed a retrospective multicenter cohort study on 11,199 adults admitted for TBI between 2007 and 2012 in an inclusive Canadian trauma system. Our primary outcome measure was index hospital LOS (admission to the hospital with the highest designation level). Index LOS was compared to total LOS (all consecutive admissions related to the injury). Expected LOS was calculated by matching TBI admissions to all-diagnosis hospital admissions by age, gender, and year of admission. LOS determinants were identified using multilevel linear regression.

RESULTS

Geometric mean total LOS was 1day longer than geometric mean index LOS (12.6 versus 11.7 days). Observed index and ICU LOS were respectively 4.2days and 2.5days longer than that expected according to all-diagnosis admissions. The six most important determinants of LOS were discharge destination, severity of concomitant injuries, extracranial complications, GCS, TBI severity, and mechanical ventilation, accounting for 80% of explained variation.

CONCLUSIONS

Results of this multicenter retrospective cohort study suggest that hospital and ICU LOS for TBI admissions are 56% and 119% longer than expected according to all-diagnosis admissions, respectively. In addition, hospital LOS is underestimated when only the index visit is considered and is largely influenced by discharge destination and extracranial complications, suggesting that improvements could be achieved with better discharge planning and interventions targeting prevention of in-hospital complications. This study highlights the importance of considering TBI patients as a distinct population when allocating resources or planning quality improvement interventions.

Helicopters and injured kids: Improved survival with scene air medical transport in the pediatric trauma population

BACKGROUND

Helicopter emergency medical services (HEMS) are frequently used to transport injured children, despite unclear evidence of benefit. The study objective was to evaluate the association of HEMS compared with ground emergency medical services (GEMS) transport with outcomes in a national sample of pediatric trauma patients.

METHODS

Patients 15 years or younger undergoing scene transport by HEMS or GEMS in the National Trauma Data Bank from 2007 to 2012 were included. Propensity score matching was used to match HEMS and GEMS patients for likelihood of HEMS transport based on demographics, prehospital physiology and time, injury severity, and geographic region. Absolute standardized differences of less than 0.1 indicated adequate covariate balance between groups after matching. The primary outcome was in-hospital survival, while the secondary outcome was discharge disposition in survivors. Conditional logistic regression determined the association between HEMS versus GEMS transport with outcomes while controlling for demographics, admission physiology, injury severity, nonaccidental trauma, and in-hospital complications not accounted for in the propensity score. Subgroup analysis was performed in patients with a transport time of greater than 15 minutes to capture patients with the potential for HEMS transport.

RESULTS

A total of 25,700 HEMS/GEMS pairs were matched from 166,594 patients. Groups were well matched, with all propensity score variables having absolute standardized differences of less than 0.1. In matched patients, HEMS was associated with a 72% increase in odds of survival compared with GEMS (adjusted odds ratio, 1.72; 95% confidence interval, 1.26-2.36; p < 0.01). Transport mode was not associated with discharge disposition (p = 0.47). Subgroup analysis included 17,657 HEMS/GEMS pairs. HEMS was again associated with a significant increase in odds of survival (adjusted odds ratio, 1.81; 95% confidence interval, 1.24-2.65; p < 0.01), while transport mode was not associated with discharge disposition (p = 0.58).

CONCLUSION

Scene transport by HEMS was associated with improved odds of survival compared with GEMS in pediatric trauma patients. Further study is warranted to understand the underlying mechanisms and develop specific triage criteria for HEMS transport in this population.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Ten year maturation period in a level-I trauma center, a cohort comparison study

Purpose

Many changes have been made to improve trauma care. Improved trauma team response and usage of a hybrid resuscitation room are examples of how this trauma center has developed. The aim was to assess how the outcome of the trauma population was influenced by the maturation.

Methods

A cohort comparison, between June 2004–July 2005 and 2014, was performed. All adult trauma patients with an Injury Severity Score (ISS) >15 were included. Variables collected were: patient demographics, mechanism of trauma, total prehospital time, pre- and inhospital trauma scores, vital signs, blood values and interventions, and physician staffed helicopter emergency medical services (P-HEMS) involvement and outcome.

Results

From June 2004 to July 2005 219, patients were admitted, and for the year 2014, this was 282 patients. The 2014 cohort was significantly older (mean age of 53.6 ± 23.8 vs 45.6 ± 22.7 years). The mean RTS did not differ. P-HEMS assists increased to 116 (13.5 %). The number of CT scans, blood transfusion, and acute trauma surgical interventions decreased. Mean LOS, ICU admission, and ICU LOS did not differ. The mortality rate, however, decreased by 7.0 %, observed and predicted survival was significantly different in favour of the 2014 cohort, with a Z-score of 4.25.

Conclusion

An increase in age is seen, though trauma scores remain comparable. The number of blood products transfused and acute trauma surgical interventions performed declines. Mortality significantly decreased and a significant difference in observed and predicted survival is seen. Showing improved trauma care in our hospital, in favour of the second period.

Timing of withdrawal of life-sustaining therapies in severe traumatic brain injury: Impact on overall mortality

BACKGROUND

The care of patients with severe traumatic brain injury (TBI) is complex and confounded by uncertainty in prognoses. Studies have demonstrated significant unexplained variation in mortality between centers. Possible explanations include differences in the quality and intensity of care across centers, including the appropriateness and timing of withdrawal of life-sustaining therapies. We postulated that centers with a preponderance of early deaths might have a more pessimistic approach to the TBI patient, which would be reflected in an increased hospital TBI-related mortality.

METHODS

This is a retrospective cohort study. Time to death was used as a proxy for time to withdrawal of life-sustaining therapies. Centers were classified as early or late based on when the majority (75th percentile) of their TBI-related deaths occurred. We evaluated the association between adjusted mortality and center classification using a hierarchical multivariable model. Two hundred trauma centers contributing data to the American College of Surgeons Trauma Quality Improvement Program from 2010 through 2013 were involved. The cohort included 17,505 patients with severe isolated TBI.

RESULTS

One hundred eight centers were classified as early centers. The 75th percentile for time to death was 4 days among early centers versus 7 days in late centers. Mortality was 34% and 33%, respectively. After adjustment for case mix, care in an early center was not associated with increased odds of death (adjusted odds ratio, 0.95; 95% confidence interval, 0.83-1.09). Higher odds of death were independently associated with age, Glasgow Coma Scale (GCS) score, head Abbreviated Injury Scale (AIS) score, multiple comorbidities, traumatic subarachnoid hemorrhage, intracerebral mass lesions, brainstem lesions, and signs of compressed or absent basal cisterns.

CONCLUSION

Centers rendering early decisions related to withdrawal of life-sustaining therapies in TBI patients, as measured by time until death, do not have worse outcomes than those making later decisions. How and when these decisions are made requires further exploration to balance an opportunity for clinical improvement with appropriate resource use.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level III.

Helicopter transport improves survival following injury in the absence of a time-saving advantage

BACKGROUND

Although survival benefits have been shown at the population level, it remains unclear what drives the outcome benefits for helicopter emergency medical services (HEMS) in trauma. Although speed is often cited as the vital factor of HEMS, we hypothesized a survival benefit would exist in the absence of a time savings over ground emergency medical services (GEMS). The objective was to examine the association of survival with HEMS compared with GEMS transport across similar prehospital transport times.

METHODS

We used a retrospective cohort of scene HEMS and GEMS transports in the National Trauma Databank (2007-2012). Propensity score matching was used to match HEMS and GEMS subjects on the likelihood of HEMS transport. Subjects were stratified by prehospital transport times in 5-minute increments. Conditional logistic regression determined the association of HEMS with survival across prehospital transport times strata controlling for confounders. Transport distance was estimated from prehospital transport times and average HEMS/GEMS transport speeds.

RESULTS

There were 155,691 HEMS/GEMS pairs matched. HEMS had a survival benefit over GEMS for prehospital transport times between 6 and 30 minutes. This benefit ranged from a 46% increase in odds of survival between 26 and 30 minutes (adjusted odds ratio [AOR], 1.46; 95% CI, 1.11-1.93; P < .01) to an 80% increase in odds of survival between 16 and 20 minutes (AOR, 1.80; 95% CI, 1.51-2.14; P < .01). This prehospital transport times window corresponds to estimated transport distance between 14.3 and 71.3 miles for HEMS and 3.3 and 16.6 miles for GEMS.

CONCLUSION

When stratified by prehospital transport times, HEMS had a survival benefit concentrated in a window between 6 and 30 minutes. Because there was no time-savings advantage for HEMS, these findings may reflect care delivered by HEMS providers.