The trauma risk adjustment model: a new model for evaluating trauma care

Internal and external validation of an updated ICD-10-CA to AIS-2005 update 2008 algorithm

BACKGROUND

Administrative data are a powerful tool for population-level trauma research but lack the trauma-specific diagnostic and injury severity codes needed for risk-adjusted comparative analyses. The objective of this study was to validate an algorithm to derive Abbreviated Injury Scale (AIS-2005 update 2008) severity scores from Canadian International Classification of Diseases (ICD-10-CA) diagnostic codes in administrative data.

METHODS

This was a retrospective cohort study using data from the 2009 to 2017 Ontario Trauma Registry for the internal validation of the algorithm. This registry includes all patients treated at a trauma center who sustained a moderate or severe injury or were assessed by a trauma team. It contains both ICD-10-CA codes and injury scores assigned by expert abstractors. We used Cohen's kappa (𝜅) coefficient to compare AIS-2005 Update 2008 scores assigned by expert abstractors to those derived using the algorithm and the intraclass correlation coefficient to compare assigned and derived Injury Severity Scores. Sensitivity and specificity for detection of a severe injury (AIS score, ≥ 3) were then calculated. For the external validation of the algorithm, we used administration data to identify adults who either died in an emergency department or were admitted to hospital in Ontario secondary to a traumatic injury (2009-2017). Logistic regression was used to evaluate the discriminative ability and calibration of the algorithm.

RESULTS

Of 41,869 patients in the Ontario Trauma Registry, 41,793 (99.8%) had at least one diagnosis matched to the algorithm. Evaluation of AIS scores assigned by expert abstractors and those derived using the algorithm demonstrated a high degree of agreement in identification of patients with at least one severe injury (𝜅 = 0.75; 95% confidence interval [CI], 0.74-0.76). Likewise, algorithm-derived scores had a strong ability to rule in or out injury with AIS ≥ 3 (specificity, 78.5%; 95% CI, 77.7-79.4; sensitivity, 95.1; 95% CI, 94.8-95.3). There was strong correlation between expert abstractor-assigned and crosswalk-derived Injury Severity Score (intraclass correlation coefficient, 0.80; 95% CI, 0.80-0.81). Among the 130,542 patients identified using administrative data, the algorithm retained its discriminative properties.

CONCLUSION

Our ICD-10-CA to AIS-2005 update 2008 algorithm produces reliable estimates of injury severity and retains its discriminative properties with administrative data. Our findings suggest that this algorithm can be used for risk adjustment of injury outcomes when using population-based administrative data.

LEVEL OF EVIDENCE

Diagnostic Tests/Criteria; Level II.

Injury outcomes across Canadian trauma systems: a historical cohort study

PURPOSE

Most North American trauma systems have designated trauma centres (TCs) including level I (ultraspecialized high-volume metropolitan centres), level II (specialized medium-volume urban centres), and/or level III (semirural or rural centres). Trauma system configuration varies across provinces and it is unclear how these differences influence patient distributions and outcomes. We aimed to compare patient case mix, case volumes, and risk-adjusted outcomes of adults with major trauma admitted to designated level I, II, and III TCs across Canadian trauma systems.

METHODS

In a national historical cohort study, we extracted data from Canadian provincial trauma registries on major trauma patients treated between 2013 and 2018 in all designated level I, II, or III TCs in British Columbia, Alberta, Quebec, and Nova Scotia; level I and II TCs in New Brunswick; and four TCs in Ontario. We used multilevel generalized linear models to compare mortality and intensive care unit (ICU) admission and competitive risk models for hospital and ICU length of stay (LOS). Ontario could not be included in outcome comparisons because there were no population-based data from this province.

RESULTS

The study sample comprised 50,959 patients. Patient distributions in level I and II TCs were similar across provinces but we observed significant differences in case mix and volumes for level III TCs. There was low variation in risk-adjusted mortality and LOS across provinces and TCs but interprovincial and intercentre variation in risk-adjusted ICU admission was high.

CONCLUSIONS

Our results suggest that differences in the functional role of TCs according to their designation level across provinces leads to significant variations in the distribution of patients, case volumes, resource use, and clinical outcomes. These results highlight opportunities to improve Canadian trauma care and underline the need for standardized population-based injury data to support national quality improvement efforts.

The European guideline on management of major bleeding and coagulopathy following trauma: fifth edition

BACKGROUND

Severe traumatic injury continues to present challenges to healthcare systems around the world, and post-traumatic bleeding remains a leading cause of potentially preventable death among injured patients. Now in its fifth edition, this document aims to provide guidance on the management of major bleeding and coagulopathy following traumatic injury and encourages adaptation of the guiding principles described here to individual institutional circumstances and resources.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004, and the current author group included representatives of six relevant European professional societies. The group applied a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were re-examined and revised based on scientific evidence that has emerged since the previous edition and observed shifts in clinical practice. New recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated.

RESULTS

Advances in our understanding of the pathophysiology of post-traumatic coagulopathy have supported improved management strategies, including evidence that early, individualised goal-directed treatment improves the outcome of severely injured patients. The overall organisation of the current guideline has been designed to reflect the clinical decision-making process along the patient pathway in an approximate temporal sequence. Recommendations are grouped behind the rationale for key decision points, which are patient- or problem-oriented rather than related to specific treatment modalities. While these recommendations provide guidance for the diagnosis and treatment of major bleeding and coagulopathy, emerging evidence supports the author group's belief that the greatest outcome improvement can be achieved through education and the establishment of and adherence to local clinical management algorithms.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. If incorporated into local practice, these clinical practice guidelines have the potential to ensure a uniform standard of care across Europe and beyond and better outcomes for the severely bleeding trauma patient.

Impact of comorbidities on the prognoses of trauma patients: Analysis of a hospital-based trauma registry database

Here we conducted a retrospective analysis of hospital-based trauma registry database for evaluating the impacts of comorbidities on the prognosis for traumatized patients using Index of Coexistent Comorbidity Disease (ICED) scores. We analyzed the data of patients with blunt trauma who visited emergency department between January 1, 2011, and December 31, 2015 in Chang-Gung Memorial Hospital, Keelung branch, a single level I trauma center in the Northern Taiwan. All consecutive patients with blunt trauma who admitted to the intensive care unit or ordinary ward after initial managements in the emergency department were included. We measured the hospital mortality of blunt traumatized patients using alive discharge as a competing risk. To investigate conditional independence of mortality and ICED scores given Injury Severity Score (ISS), we used log-linear models for modeling independence structures. Overall, we included 4997 patients (median age [IQR], 59 years old (44–75 years); 55.3% male). The mortality rate of blunt traumatized patients was higher in the higher ICED scores group compared to lower ICED scores group (4.7% vs 1.8%, p < 0.001). Meanwhile, the higher ICED scores group were associated with older age, higher ISS, and longer hospital stay than lower ICED scores group. Higher ICED group had higher probability of transition-to-death and lower probability of transition-to-discharge under the competing risk model. In the multivariable analysis of transition-specific Cox models, higher ICED group were associated with higher risk for hospital mortality compared to lower ICED group (HR 1.60; [95% CI 1.04–2.47]; p = 0.032). Also, higher ICED group were associated with lower probability of transition-to-discharge (HR 0.79; [95%CI 0.73–0.86]; p < 0.001). Additionally, higher ICED scores accounted for hospital mortality among patients with ISS < 25. In conclusion, our study suggested that severity of comorbidity was associated with higher hospital mortality among traumatized patients, particularly lower ISS.

Canadian benchmarks for acute injury care

BACKGROUND

Acute care injury outcomes vary substantially across Canadian provinces and trauma centres. Our aim was to develop Canadian benchmarks to monitor mortality and hospital length of stay (LOS) for injury admissions.

METHODS

Benchmarks were derived using data from the Canadian National Trauma Registry on patients with major trauma admitted to any level I or II trauma centre in Canada and from the following patient subgroups: isolated traumatic brain injury (TBI), isolated thoracoabdominal injury, multisystem blunt injury, age 65 years or older. We assessed predictive validity using measures of discrimination and calibration, and performed sensitivity analyses to assess the impact of replacing analytically complex methods (multiple imputation, shrinkage estimates and flexible modelling) with simple models that can be implemented locally.

RESULTS

The mortality risk adjustment model had excellent discrimination and calibration (area under the receiver operating characteristic curve 0.886, Hosmer-Lemeshow 36). The LOS risk-adjustment model predicted 29% of the variation in LOS. Overall, observed:expected ratios of mortality and mean LOS generated by an analytically simple model correlated strongly with those generated by analytically complex models (r > 0.95, κ on outliers > 0.90).

CONCLUSION

We propose Canadian benchmarks that can be used to monitor quality of care in Canadian trauma centres using Excel (see the appendices, available at canjsurg.ca). The program can be implemented using local trauma registries, providing that at least 100 patients are available for analysis.

Assessing Field Triage Decisions and the International Classification Injury Severity Score (ICISS) at Predicting Outcomes of Trauma Patients

Florida considers the International Classification Injury Severity Score (ICISS) from hospital discharges within a geographic region in the apportionment of trauma centers (TCs). Patients with an ICISS <0.85 are considered to require triage to a TC, yet many are triaged to an emergency department (ED). We assess outcomes of those with an ICISS <0.85 by the actual triage decision of emergency medical services (EMS). From October 2011 to October 2013, 39,021 consecutive admissions with injury ICD-9 codes were analyzed. ICISS was calculated from the product of the survival risk ratios for a patient's three worst injuries. Outcomes were compared between patients with ICISS <0.85 either triaged to the ED or its separate, neighboring, free-standing TC at a large urban hospital. A total of 32,191 (83%) patients were triaged to the ED by EMS and 6,827 (17%) were triaged to the TC. Of these, 2544 had an ICISS <0.85, with 2145 (84%) being triaged to the TC and 399 (16%) to the ED. In these patients, those taken to the TC more often required admission, and those taken to the ED had better outcomes. When the confounders influencing triage to an ED or a TC are eliminated, those triaged by EMS to the ED rather than the TC had better overall outcomes. EMS providers better identified patients at risk for mortality than did the retrospective application of ICISS. ICISS <0.85 does not identify the absolute need for TC as EMS providers were able to appropriately triage a large portion of this population to the ED.

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.

The European guideline on management of major bleeding and coagulopathy following trauma: fourth edition

BACKGROUND

Severe trauma continues to represent a global public health issue and mortality and morbidity in trauma patients remains substantial. A number of initiatives have aimed to provide guidance on the management of trauma patients. This document focuses on the management of major bleeding and coagulopathy following trauma and encourages adaptation of the guiding principles to each local situation and implementation within each institution.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004 and included representatives of six relevant European professional societies. The group used a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were reconsidered and revised based on new scientific evidence and observed shifts in clinical practice; new recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated. This guideline represents the fourth edition of a document first published in 2007 and updated in 2010 and 2013.

RESULTS

The guideline now recommends that patients be transferred directly to an appropriate trauma treatment centre and encourages use of a restricted volume replacement strategy during initial resuscitation. Best-practice use of blood products during further resuscitation continues to evolve and should be guided by a goal-directed strategy. The identification and management of patients pre-treated with anticoagulant agents continues to pose a real challenge, despite accumulating experience and awareness. The present guideline should be viewed as an educational aid to improve and standardise the care of the bleeding trauma patients across Europe and beyond. This document may also serve as a basis for local implementation. Furthermore, local quality and safety management systems need to be established to specifically assess key measures of bleeding control and outcome.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. The implementation of locally adapted treatment algorithms should strive to achieve measureable improvements in patient outcome.

[Multidisciplinary consensus document on the management of massive haemorrhage (HEMOMAS document)]

Massive haemorrhage is common and often associated with high morbidity and mortality. We perform a systematic review of the literature, with extraction of the recommendations from the existing evidences because of the need for its improvement and the management standardization. From the results we found, we wrote a multidisciplinary consensus document. We begin with the agreement in the definitions of massive haemorrhage and massive transfusion, and we do structured recommendations on their general management (clinical assessment of bleeding, hypothermia management, fluid therapy, hypotensive resuscitation and damage control surgery), blood volume monitoring, blood products transfusion (red blood cells, fresh frozen plasma, platelets and their best transfusion ratio), and administration of hemostatic components (prothrombin complex, fibrinogen, factor VIIa, antifibrinolytic agents).

Multidisciplinary consensus document on the management of massive haemorrhage (HEMOMAS document)

Massive haemorrhage is common and often associated with high morbidity and mortality. We perform a systematic review of the literature, with extraction of the recommendations from the existing evidences because of the need for its improvement and the management standardization. From the results we found, we wrote a multidisciplinary consensus document. We begin with the agreement in the definitions of massive haemorrhage and massive transfusion, and we do structured recommendations on their general management (clinical assessment of bleeding, hypothermia management, fluid therapy, hypotensive resuscitation and damage control surgery), blood volume monitoring, blood products transfusion (red blood cells, fresh frozen plasma, platelets and their best transfusion ratio), and administration of hemostatic components (prothrombin complex, fibrinogen, factor VIIa, antifibrinolytic agents).

Donabedian's structure-process-outcome quality of care model: Validation in an integrated trauma system

BACKGROUND

According to Donabedian's health care quality model, improvements in the structure of care should lead to improvements in clinical processes that should in turn improve patient outcome. This model has been widely adopted by the trauma community but has not yet been validated in a trauma system. The objective of this study was to assess the performance of an integrated trauma system in terms of structure, process, and outcome and evaluate the correlation between quality domains.

METHODS

Quality of care was evaluated for patients treated in a Canadian provincial trauma system (2005-2010; 57 centers, n = 63,971) using quality indicators (QIs) developed and validated previously. Structural performance was measured by transposing on-site accreditation visit reports onto an evaluation grid according to American College of Surgeons criteria. The composite process QI was calculated as the average sum of proportions of conformity to 15 process QIs derived from literature review and expert opinion. Outcome performance was measured using risk-adjusted rates of mortality, complications, and readmission as well as hospital length of stay (LOS). Correlation was assessed with Pearson's correlation coefficients.

RESULTS

Statistically significant correlations were observed between structure and process QIs (r = 0.33), and process and outcome QIs (r = -0.33 for readmission, r = -0.27 for LOS). Significant positive correlations were also observed between outcome QIs (r = 0.37 for mortality-readmission; r = 0.39 for mortality-LOS and readmission-LOS; r = 0.45 for mortality-complications; r = 0.34 for readmission-complications; 0.63 for complications-LOS).

CONCLUSION

Significant correlations between quality domains observed in this study suggest that Donabedian's structure-process-outcome model is a valid model for evaluating trauma care. Trauma centers that perform well in terms of structure also tend to perform well in terms of clinical processes, which in turn has a favorable influence on patient outcomes.

LEVEL OF EVIDENCE

Prognostic study, level III.

Derivation and validation of a quality indicator of acute care length of stay to evaluate trauma care

OBJECTIVE

To derive and internally validate a quality indicator (QI) for acute care length of stay (LOS) after admission for injury.

BACKGROUND

Unnecessary hospital days represent an estimated 20% of total LOS implying an important waste of resources as well as increased patient exposure to hospital-acquired infections and functional decline.

METHODS

This study is based on a multicenter, retrospective cohort from a Canadian provincial trauma system (2005-2010; 57 trauma centers; n = 57,524). Data were abstracted from the provincial trauma registry and the hospital discharge database. Candidate risk factors were identified by expert consensus and selected for model derivation using bootstrap resampling. The validity of the QI was evaluated in terms of interhospital discrimination, construct validity, and forecasting.

RESULTS

The risk adjustment model explains 37% of the variation in LOS. The QI discriminates well across trauma centers (coefficient of variation = 0.02, 95% confidence interval: 0.011-0.028) and is correlated with the QI on processes of care (r = -0.32), complications (r = 0.66), unplanned readmissions (r = 0.38), and mortality (r = 0.35). Performance in 2005 to 2007 was predictive of performance in 2008 to 2010 (r = 0.80).

CONCLUSIONS

We have developed a QI on the basis of risk-adjusted LOS to evaluate trauma care that can be implemented with routinely collected data. The QI is based on a robust risk adjustment model with good internal and temporal validity, and demonstrates good properties in terms of discrimination, construct validity, and forecasting. This QI can be used to target interventions to reduce LOS, which will lead to more efficient resource use and may improve patient outcomes after injury.

Outcome prediction modelling for trauma patients: a German perspective

Prognostic models may have some clinical advantages when predicting the outcome of individual trauma patients is relevant. The variables that are predicted to have a negative effect on outcome in a model can also guide clinicians in their resuscitation attempt of trauma victims.

Update of the trauma risk adjustment model of the TraumaRegister DGU™: the Revised Injury Severity Classification, version II

INTRODUCTION

The TraumaRegister DGU™ (TR-DGU) has used the Revised Injury Severity Classification (RISC) score for outcome adjustment since 2003. In recent years, however, the observed mortality rate has fallen to about 2% below the prognosis, and it was felt that further prognostic factors, like pupil size and reaction, should be included as well. Finally, an increasing number of cases did not receive a RISC prognosis due to the missing values. Therefore, there was a need for an updated model for risk of death prediction in severely injured patients to be developed and validated using the most recent data.

METHODS

The TR-DGU has been collecting data from severely injured patients since 1993. All injuries are coded according to the Abbreviated Injury Scale (AIS, version 2008). Severely injured patients from Europe (ISS ≥ 4) documented between 2010 and 2011 were selected for developing the new score (n = 30,866), and 21,918 patients from 2012 were used for validation. Age and injury codes were required, and transferred patients were excluded. Logistic regression analysis was applied with hospital mortality as the dependent variable. Results were evaluated in terms of discrimination (area under the receiver operating characteristic curve, AUC), precision (observed versus predicted mortality), and calibration (Hosmer-Lemeshow goodness-of-fit statistic).

RESULTS

The mean age of the development population was 47.3 years; 71.6% were males, and the average ISS was 19.3 points. Hospital mortality rate was 11.5% in this group. The new RISC II model consists of the following predictors: worst and second-worst injury (AIS severity level), head injury, age, sex, pupil reactivity and size, pre-injury health status, blood pressure, acidosis (base deficit), coagulation, haemoglobin, and cardiopulmonary resuscitation. Missing values are included as a separate category for every variable. In the development and the validation dataset, the new RISC II outperformed the original RISC score, for example AUC in the development dataset 0.953 versus 0.939.

CONCLUSIONS

The updated RISC II prognostic score has several advantages over the previous RISC model. Discrimination, precision and calibration are improved, and patients with partial missing values could now be included. Results were confirmed in a validation dataset.

Cost-effectiveness of helicopter versus ground emergency medical services for trauma scene transport in the United States

STUDY OBJECTIVE

We determine the minimum mortality reduction that helicopter emergency medical services (EMS) should provide relative to ground EMS for the scene transport of trauma victims to offset higher costs, inherent transport risks, and inevitable overtriage of patients with minor injury.

METHODS

We developed a decision-analytic model to compare the costs and outcomes of helicopter versus ground EMS transport to a trauma center from a societal perspective during a patient's lifetime. We determined the mortality reduction needed to make helicopter transport cost less than $100,000 and $50,000 per quality-adjusted life-year gained compared with ground EMS. Model inputs were derived from the National Study on the Costs and Outcomes of Trauma, National Trauma Data Bank, Medicare reimbursements, and literature. We assessed robustness with probabilistic sensitivity analyses.

RESULTS

Helicopter EMS must provide a minimum of a 15% relative risk reduction in mortality (1.3 lives saved/100 patients with the mean characteristics of the National Study on the Costs and Outcomes of Trauma cohort) to cost less than $100,000 per quality-adjusted life-year gained and a reduction of at least 30% (3.3 lives saved/100 patients) to cost less than $50,000 per quality-adjusted life-year. Helicopter EMS becomes more cost-effective with significant reductions in patients with minor injury who are triaged to air transport or if long-term disability outcomes are improved.

CONCLUSION

Helicopter EMS needs to provide at least a 15% mortality reduction or a measurable improvement in long-term disability to compare favorably with other interventions considered cost-effective. Given current evidence, it is not clear that helicopter EMS achieves this mortality or disability reduction. Reducing overtriage of patients with minor injury to helicopter EMS would improve its cost-effectiveness.

Level of agreement between prehospital and emergency department vital signs in trauma patients

OBJECTIVES

Describe the level of agreement between prehospital (emergency medical service [EMS]) and ED vital signs in a group of trauma patients transported to an inner city Major Trauma Centre. We also sought to determine factors associated with differences in recorded vital sign measurements.

METHODS

All adult patients meeting trauma triage criteria and transported directly from scene of injury by New South Wales Ambulance to our institution were included. The primary outcome was the difference in vital signs: heart rate (HR), systolic blood pressure (SBP), respiratory rate (RR) and Glasgow Coma Scale (GCS), between ED and EMS recorded measurements. Agreement was assessed using intraclass correlation coefficients and enhanced Bland-Altman plots. Multivariable linear regression models were used to determine factors associated with vital sign differences.

RESULTS

The 1181 trauma patients met inclusion criteria. Intraclass correlation coefficients were as follows: GCS 0.74 (95% confidence interval [CI], 0.37, 1.12); HR 0.41 (95% CI, 0.30, 0.53); SBP 0.37 (95% CI, 0.27, 0.46); and RR 0.29 (95% CI, 0.06, 0.51). Bland-Altman derived 95% limits of agreement lay outside a priori limits of clinical agreement for SBP and RR and were within limits of clinical agreement for GCS and HR. SBP and HR differences were associated with prehospital airway and fluid intervention.

CONCLUSIONS

Agreement was demonstrated between EMS and ED GCS scores but not RR and SBP recordings. Discrepancies appeared to reflect physiological changes in response to EMS initiated interventions. Trauma triage algorithms and risk models might need to take these measurement differences, and factors associated with them, into account.

Major trauma registry of Navarre (Spain): the accuracy of different survival prediction models

OBJECTIVE

To determine which factors predict death among trauma patients who are alive on arrival at hospital.

METHODS

Design prospective cohort study method. Data were collected on 378 trauma patients who were initially delivered by the emergency medical services of Navarre (Spain) with multiple injuries with a new injury severity score of 15 or more in 2011-2012. These data related to age, gender, presence of premorbid conditions, abbreviated injury score, injury severity score, new injury severity score (NISS), revised trauma score (RTS), and prehospital and hospital response times. Bivariate analysis was used to show the association between each variable and time until death. Mortality prediction was modeled using logistic regression analysis.

RESULTS

The variables related to the end result were the age of the patient, associated comorbidity, NISS, and hospital RTS. Two models were formulated: in one, the variables used were quantitative, while in the other model these variables were converted into dichotomous qualitative variables. The predictive capability of the two models was compared with the trauma and injury severity score using the area under the curve. The predictive capacities of the three models had areas under the curve of 0.93, 0.88, and 0.87. The response times of the Navarre emergency services system, measured as the sum of the time taken to reach the hospital (median time of 65 min), formulate computed tomography (46 min), and perform crucial surgery (115 min), when required, were not taken into account.

CONCLUSION

Age, premorbid conditions, hospital RTS, and NISS are significant predictors of death after trauma. The time intervals between the accident and arrival at the hospital, arrival at the hospital and the first computed tomography scan or the first crucial emergency intervention, do not appear to affect the risk of death.

Comparing regression-adjusted mortality to standardized mortality ratios for trauma center profiling

Background:

Trauma center profiling is commonly performed with Standardized Mortality Ratios (SMRs). However, comparison of SMRs across trauma centers with different case mix can induce confounding leading to biased trauma center ranks. We hypothesized that Regression-Adjusted Mortality (RAM) estimates would provide a more valid measure of trauma center performance than SMRs.

Objective:

Compare trauma center ranks generated by RAM estimates to those generated by SMRs.

Materials and Methods:

The study was based on data from a provincial Trauma Registry (1999-2006; n = 88,235). SMRs were derived as the ratio of observed to expected deaths using: (1) the study population as an internal standard, (2) the US National Trauma Data Bank as an external standard. The expected death count was calculated as the sum of mortality probabilities for all patients treated in a hospital conditional on the injury severity score, the revised trauma score, and age. RAM estimates were obtained directly from a hierarchical logistic regression model.

Results:

Crude mortality was 5.4% and varied between 1.3% and 13.5% across the 59 trauma centers. When trauma center ranks from internal SMRs and RAM were compared, 49 out of 59 centers changed rank and six centers changed by more than five ranks. When trauma center ranks from external SMRs and RAM were compared, 55 centers changed rank and 17 changed by more than five ranks.

Conclusions:

The results of this study suggest that the use of SMRs to rank trauma centers in terms of mortality may be misleading. RAM estimates represent a potentially more valid method of trauma center profiling.

Systematic review of predictive performance of injury severity scoring tools

Many injury severity scoring tools have been developed over the past few decades. These tools include the Injury Severity Score (ISS), New ISS (NISS), Trauma and Injury Severity Score (TRISS) and International Classification of Diseases (ICD)-based Injury Severity Score (ICISS). Although many studies have endeavored to determine the ability of these tools to predict the mortality of injured patients, their results have been inconsistent. We conducted a systematic review to summarize the predictive performances of these tools and explore the heterogeneity among studies. We defined a relevant article as any research article that reported the area under the Receiver Operating Characteristic curve as a measure of predictive performance. We conducted an online search using MEDLINE and Embase. We evaluated the quality of each relevant article using a quality assessment questionnaire consisting of 10 questions. The total number of positive answers was reported as the quality score of the study. Meta-analysis was not performed due to the heterogeneity among studies. We identified 64 relevant articles with 157 AUROCs of the tools. The median number of positive answers to the questionnaire was 5, ranging from 2 to 8. Less than half of the relevant studies reported the version of the Abbreviated Injury Scale (AIS) and/or ICD (37.5%). The heterogeneity among the studies could be observed in a broad distribution of crude mortality rates of study data, ranging from 1% to 38%. The NISS was mostly reported to perform better than the ISS when predicting the mortality of blunt trauma patients. The relative performance of the ICSS against the AIS-based tools was inconclusive because of the scarcity of studies. The performance of the ICISS appeared to be unstable because the performance could be altered by the type of formula and survival risk ratios used. In conclusion, high-quality studies were limited. The NISS might perform better in the mortality prediction of blunt injuries than the ISS. Additional studies are required to standardize the derivation of the ICISS and determine the relative performance of the ICISS against the AIS-based tools.

Trauma centre outcome performance: a comparison of young adults and geriatric patients in an inclusive trauma system

BACKGROUND

Elderly trauma patients represent a unique clientele requiring specialised care but they rarely benefit from standardised care strategies within trauma systems. We aimed to evaluate whether trauma centres with lower/higher than expected mortality amongst patients <65 years of age have similar results for geriatric patients. A secondary objective was to compare transfer to level I/II trauma centres across age groups.

METHODS

The study was based on data from a Canadian provincial trauma registry (1999-2006). Outcome performance was evaluated with estimates of risk-adjusted 30-day mortality generated for each of the system's 57 adult trauma centres. Agreement in performance results was evaluated with correlation coefficients.

RESULTS

The study sample comprised 55,283 young adults (3.5% mortality) and 30,960 geriatric patients (8.2% mortality). The two age groups only had one out of six outliers in common. Hospital ranks amongst young adults were not correlated to those assigned amongst geriatric patients (r = 0.01, 95%CI -0.25;0.27). Correlation was also low for patients with major trauma (r = 0.20, 95%CI -0.06;0.44). Amongst patients with severe head injuries initially received in a level III/IV centre, 81% of young adults versus 71% of geriatric patients were transferred to a level I/II centre (p<0.0001).

CONCLUSIONS

Trauma centres that have low risk-adjusted mortality for young adults do not necessarily do so for geriatric patients. In addition, geriatric patients with severe head injuries are less likely to be treated in neurosurgical trauma centres. Further research is needed to identify determinants of inter-hospital variation in outcome for geriatric trauma patients.

The use of the Revised Trauma Score as an entry criterion in traumatic hemorrhagic shock studies: data from the DCLHb clinical trials

INTRODUCTION

The Revised Trauma Score (RTS) has been proposed as an entry criterion to identify patients with mid-range survival probability for traumatic hemorrhagic shock studies.

HYPOTHESIS/PROBLEM

Determination of which of four RTS strata (1-3.99, 2-4.99, 1-4.99, and 2-5.99) identifies patients with predicted and actual mortality rates near 50% for use as an entry criterion in traumatic hemorrhagic shock clinical trials.

METHODS

Existing database analysis in which demographic and injury severity data from two prior international Diaspirin Cross-Linked Hemoglobin (DCLHb) clinical trials were used to identify an RTS range that could be an optimal entry criterion in order to find the population of trauma patients with mid-range predicted and actual mortality rates.

RESULTS

Of 208 study patients, the mean age was 37 years, 65% sustained blunt trauma, 49% received DCLHb, and 57% came from the European Union study arm. The mean values were: ISS, 31 (SD = 18); RTS, 5.6 (SD = 1.8); and Glasgow Coma Scale (GCS), 10.4 (SD = 4.8). The mean TRISS-predicted mortality was 34% and the actual 28-day mortality was 35%. The initially proposed 1-3.99 RTS range (n = 41) had the highest predicted (79%) and actual (71%) mortality rates. The 2-5.99 RTS range (n = 79) had a 62% predicted and 53% actual mortality, and included 76% blunt trauma patients. Removal of GCS <5 patients from this RTS 2-5.99 subgroup caused a 48% further reduction in eligible patients, leaving 41 patients (20% of 208 total patients), 66% of whom sustained a blunt trauma injury. This subgroup had 54% predicted and 49% actual mortality rates. Receiver operator curve (ROC) analysis found the GCS to be as predictive of mortality as the RTS, both in the total patient population and in the RTS 2-5.99 subgroup.

CONCLUSION

The use of an RTS 2-5.99 inclusion criterion range identifies a traumatic hemorrhagic shock patient subgroup with predicted and actual mortality that approach the desired 50% rate. The exclusion of GCS <5 from this RTS 2-5.99 subgroup patients yields a smaller, more uniform patient subgroup whose mortality is more likely related to hemorrhagic shock than traumatic brain injury. Future studies should examine whether the RTS or other physiologic criteria such as the GCS score are most useful as traumatic hemorrhagic shock study entry criteria.

Definition of mortality for trauma center performance evaluation: a comparative study

OBJECTIVE

Mortality is widely used as a performance indicator to evaluate the quality of trauma care, but there is no consensus on the most appropriate definition. Our objective was to evaluate the influence of the definition of mortality in terms of the place (in-hospital or postdischarge) and time (30 days and 3, 6, and 12 months) of death on the results of trauma center performance evaluations according to the patients' ages.

DESIGN

Multicenter retrospective cohort study.

SETTING

Inclusive Canadian provincial trauma system.

PATIENTS

Adults admitted between 1999 and 2006 with a maximum abbreviated injury severity score≥3 (n=47,261).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Trauma registry data were linked to vital statistics data to obtain mortality up to 12 months postadmission. Observed mortality was compared to that expected according to provincial population mortality rates. Trauma center performance was evaluated with risk-adjusted mortality estimates. Agreement between performance results based on different definitions of mortality was evaluated with correlation coefficients; >.9 was considered acceptable. Analyses were stratified by predefined age categories (16-64, 65-84, and ≥85 yrs). A total of 3,338 patients (7%) died in-hospital, and 1,794 patients (4%) died postdischarge. Among patients 16-64 yrs old, 30-day hospital mortality represented 83% of all deaths and correlation coefficients across all definitions of mortality were >.9. In patients 65-84 yrs old, 30-day hospital mortality represented 52% of all deaths, observed mortality reached expected rates at around 6 months, and agreement across mortality definitions was low.

CONCLUSIONS

We observed an important variation in performance evaluation results across definitions of mortality, specifically in patients aged≥65 yrs. Half of the deaths among elders occurred later than 30 days following admission, including a significant number postdischarge. Results suggest that if performance evaluations include elderly patients, data on postdischarge mortality up to 6 months following admission are required.

Influence of socioeconomic status on trauma center performance evaluations in a Canadian trauma system

BACKGROUND

Trauma center performance evaluations generally include adjustment for injury severity, age, and comorbidity. However, disparities across trauma centers may be due to other differences in source populations that are not accounted for, such as socioeconomic status (SES). We aimed to evaluate whether SES influences trauma center performance evaluations in an inclusive trauma system with universal access to health care.

STUDY DESIGN

The study was based on data collected between 1999 and 2006 in a Canadian trauma system. Patient SES was quantified using an ecologic index of social and material deprivation. Performance evaluations were based on mortality adjusted using the Trauma Risk Adjustment Model. Agreement between performance results with and without additional adjustment for SES was evaluated with correlation coefficients.

RESULTS

The study sample comprised a total of 71,784 patients from 48 trauma centers, including 3,828 deaths within 30 days (4.5%) and 5,549 deaths within 6 months (7.7%). The proportion of patients in the highest quintile of social and material deprivation varied from 3% to 43% and from 11% to 90% across hospitals, respectively. The correlation between performance results with or without adjustment for SES was almost perfect (r = 0.997; 95% CI 0.995-0.998) and the same hospital outliers were identified.

CONCLUSIONS

We observed an important variation in SES across trauma centers but no change in risk-adjusted mortality estimates when SES was added to adjustment models. Results suggest that after adjustment for injury severity, age, comorbidity, and transfer status, disparities in SES across trauma center source populations do not influence trauma center performance evaluations in a system offering universal health coverage.

The regionalization of pediatric health care

Regionalization of health care is a method of providing high-quality, cost-efficient health care to the largest number of patients. Within pediatric medicine, regionalization has been undertaken in 2 areas: neonatal intensive care and pediatric trauma care. The supporting literature for the regionalization of these areas demonstrates the range of studies within this field: studies of neonatal intensive care primarily compare different levels of hospitals, whereas studies of pediatric trauma care primarily compare the impact of institutionalizing a trauma system in a single geographic region. However, neither specialty has been completely regionalized, possibly because of methodologic deficiencies in the evidence base. Research with improved study designs, controlling for differences in illness severity between different hospitals; a systems approach to regionalization studies; and measurement of parental preferences will improve the understanding of the advantages and disadvantages of regionalizing pediatric medicine and will ultimately optimize the outcomes of children.

Influence of routine computed tomography on predicted survival from blunt thoracoabdominal trauma

Introduction

Many scoring systems have been proposed to predict the survival of trauma patients. This study was performed to evaluate the influence of routine thoracoabdominal computed tomography (CT) on the predicted survival according to the trauma injury severity score (TRISS).

Patients and methods

1,047 patients who had sustained a high-energy blunt trauma over a 3-year period were prospectively included in the study. All patients underwent physical examination, conventional radiography of the chest, thoracolumbar spine and pelvis, abdominal sonography, and routine thoracoabdominal CT. From this group with routine CT, we prospectively defined a selective CT (sub)group for cases with abnormal physical examination and/or conventional radiography and/or sonography. Type and extent of injuries were recorded for both the selective and the routine CT groups. Based on the injuries found by the two different CT algorithms, we calculated the injury severity scores (ISS) and predicted survivals according to the TRISS methodology for the routine and the selective CT algorithms.

Results

Based on injuries detected by the selective CT algorithm, the mean ISS was 14.6, resulting in a predicted mortality of 12.5%. Because additional injuries were found by the routine CT algorithm, the mean ISS increased to 16.9, resulting in a predicted mortality of 13.7%. The actual observed mortality was 5.4%.

Conclusion

Routine thoracoabdominal CT in high-energy blunt trauma patients reveals more injuries than a selective CT algorithm, resulting in a higher ISS. According to the TRISS, this results in higher predicted mortalities. Observed mortality, however, was significantly lower than predicted. The predicted survival according to MTOS seems to underestimate the actual survival when routine CT is used.

Trauma care in Germany: major differences in case fatality rates between centers

BACKGROUND

Recent years have seen a further decline in the nationwide case fatality rate after major trauma in Germany, but it has not been clear until now whether all centers providing trauma care achieve comparable results. We have attempted to answer this question using data from the trauma registry of the German Society for Trauma Surgery (Deutsche Gesellschaft für Unfallchirurgie, DGU).

METHODS

The standardized mortality rate of each participating center was calculated on the basis of the RISC prognostic score (Revised Injury Severity Classification) and the observed case fatality rate of the center. Results were compared across centers for the years 2004 to 2007; only the centers that provided the primary treatment of at least 100 patients during this period were included in the analysis. Data from the ten highest-scoring centers, the ten lowest-scoring centers, and the ten centers in the middle of the group were compared, and differences between them were analyzed.

RESULTS

The case fatality rate in the top ten centers was 8.7%. The corresponding rate in the bottom ten centers was approXimately twice as high, even though the injuries treated there were of comparable severity.

CONCLUSION

It is evident that the fate of a trauma patient in Germany depends partly on the center in which he or she is treated. These data were drawn from a retrospective evaluation of a case registry and should be assessed in awareness of this fact.

Goal-directed coagulation management of major trauma patients using thromboelastometry (ROTEM)-guided administration of fibrinogen concentrate and prothrombin complex concentrate

Introduction

The appropriate strategy for trauma-induced coagulopathy management is under debate. We report the treatment of major trauma using mainly coagulation factor concentrates.

Methods

This retrospective analysis included trauma patients who received ≥ 5 units of red blood cell concentrate within 24 hours. Coagulation management was guided by thromboelastometry (ROTEM^®). Fibrinogen concentrate was given as first-line haemostatic therapy when maximum clot firmness (MCF) measured by FibTEM (fibrin-based test) was <10 mm. Prothrombin complex concentrate (PCC) was given in case of recent coumarin intake or clotting time measured by extrinsic activation test (EXTEM) >1.5 times normal. Lack of improvement in EXTEM MCF after fibrinogen concentrate administration was an indication for platelet concentrate. The observed mortality was compared with the mortality predicted by the trauma injury severity score (TRISS) and by the revised injury severity classification (RISC) score.

Results

Of 131 patients included, 128 received fibrinogen concentrate as first-line therapy, 98 additionally received PCC, while 3 patients with recent coumarin intake received only PCC. Twelve patients received FFP and 29 received platelet concentrate. The observed mortality was 24.4%, lower than the TRISS mortality of 33.7% (P = 0.032) and the RISC mortality of 28.7% (P > 0.05). After excluding 17 patients with traumatic brain injury, the difference in mortality was 14% observed versus 27.8% predicted by TRISS (P = 0.0018) and 24.3% predicted by RISC (P = 0.014).

Conclusions

ROTEM^®-guided haemostatic therapy, with fibrinogen concentrate as first-line haemostatic therapy and additional PCC, was goal-directed and fast. A favourable survival rate was observed. Prospective, randomized trials to investigate this therapeutic alternative further appear warranted.

Management of bleeding following major trauma: an updated European guideline

INTRODUCTION

Evidence-based recommendations are needed to guide the acute management of the bleeding trauma patient, which when implemented may improve patient outcomes.

METHODS

The multidisciplinary Task Force for Advanced Bleeding Care in Trauma was formed in 2005 with the aim of developing a guideline for the management of bleeding following severe injury. This document presents an updated version of the guideline published by the group in 2007. Recommendations were formulated using a nominal group process, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) hierarchy of evidence and based on a systematic review of published literature.

RESULTS

Key changes encompassed in this version of the guideline include new recommendations on coagulation support and monitoring and the appropriate use of local haemostatic measures, tourniquets, calcium and desmopressin in the bleeding trauma patient. The remaining recommendations have been reevaluated and graded based on literature published since the last edition of the guideline. Consideration was also given to changes in clinical practice that have taken place during this time period as a result of both new evidence and changes in the general availability of relevant agents and technologies.

CONCLUSIONS

This guideline provides an evidence-based multidisciplinary approach to the management of critically injured bleeding trauma patients.