Comparison of the New Injury Severity Score and the Injury Severity Score

Blood Transfusion for Major Trauma in Emergency Department

Severe bleeding is the leading cause of death in patients with major trauma admitted to the emergency department. It is estimated that about 50% of deaths happen within a few minutes of the traumatic event due to massive hemorrhage; 30% of deaths are related to neurological dysfunction and typically happen within two days of trauma; and approximately 20% of patients died of multiorgan failure and sepsis within days to weeks of the traumatic event. Over the past ten years, there has been an increased understanding of the underlying mechanisms and pathophysiology associated with traumatic bleeding leading to improved management measures. Traumatic events cause significant tissue damage, with the potential for severe blood loss and the release of cytokines and hormones. They are responsible for systemic inflammation, activation of fibrinolysis pathways, and consumption of coagulation factors. As the final results of this (more complex in real life) cascade, patients can develop tissue hypoxia, acidosis, hypothermia, and severe coagulopathy, resulting in a rapid deterioration of general conditions with a high risk of mortality. Prompt and appropriate management of massive bleeding and coagulopathy in patients with trauma remains a significant challenge for emergency physicians in their daily clinical practice. Our review aims to explore literature studies providing evidence on the treatment of hemorrhage with blood support in patients with trauma admitted to the Emergency Department with a high risk of death. Advances in blood transfusion protocols, along with improvements in other resuscitation strategies, have become one of the most important issues to face and a key topic of recent clinical research in this field.

Predictive Performance for Hospital Mortality of SAPS 3, SOFA, ISS, and New ISS in Critically Ill Trauma Patients: A Validation Cohort Study

Background: It is not known whether anatomical scores perform better than general critical care scores for trauma patients admitted to the intensive care unit (ICU). We compare the predictive performance for hospital mortality of general critical care scores (SAPS 3 and SOFA) with anatomical injury-based scores (Injury Severity Score [ISS] and New ISS [NISS]). Methods: Retrospective cohort study of patients admitted to a specialized trauma ICU from a tertiary hospital in São Paulo, Brazil between May, 2012 and January, 2016. We retrieved data from the ICU database for critical care scores and calculated ISS and NISS from chart data and whole body computed tomography results. We compared the predictive performance for hospital mortality of each model through discrimination, calibration, and decision-curve analysis. Results: The sample comprised 1053 victims of trauma admitted to the ICU, with 84.2% male patients and mean age of 40 (±18) years. Main injury mechanism was blunt trauma (90.7%). Traumatic brain injury was present in 67.8% of patients; 43.3% with severe TBI. At the time of ICU admission, 846 patients (80.3%) were on mechanical ventilation and 644 (64.3%) on vasoactive drugs. Hospital mortality was 23.8% (251). Median SAPS 3 was 41; median maximum SOFA within 24 h of admission, 7; ISS, 29; and NISS, 41. AUROCs (95% CI) were: SAPS 3 = 0.786 (0.756-0.817), SOFA = 0.807 (0.778-0.837), ISS = 0.616 (0.577-0.656), and NISS = 0.689 (0.649-0.729). In pairwise comparisons, SAPS 3 and SOFA did not differ, while both outperformed the anatomical scores (p < .001). Maximum SOFA within 24 h of admission presented the best calibration and net benefit in decision-curve analysis. Conclusions: Trauma-specific anatomical scores have fair performance in critically ill trauma patients and are outperformed by SAPS 3 and SOFA. Illness severity is best characterized by organ dysfunction and physiological variables than anatomical injuries.

Injury severity score as a predictor of mortality in adult trauma patients by injury mechanism types in the United States: A retrospective observational study

Injury severity score (ISS) is commonly used in trauma registries to describe injury severity and to predict outcomes in trauma patients regardless of injury mechanism. This study examined the correlation between ISS and mortality in adult trauma patients presenting to emergency departments in the United States with different mechanisms of injury. A retrospective observational study was conducted using the 2014 Nationwide Emergency Department Sample. Patients' characteristics were stratified by mortality. Receiver operating characteristic (ROC) curves were generated for death against ISS for each mechanism of injury. A logistic regression model was conducted for each mechanism of injury to determine whether ISS (≥16 vs <16) is a predictor of mortality. The study sample consisted of 16,147,058 weighted adult trauma patients. Median age was 46 years. Slightly over half were females (51.9%). Falls, motor vehicle accidents and being struck by or against, were the most commonly reported mechanisms of injury (44.6%, 18.1%, and 15.3%, respectively). The overall mortality in the study population was 0.4%. The area under the ROC curve was highest in injuries sustained in accidents involving machinery (0.947; 95% confidence intervals [CI], 0.896-0.998), followed by motor vehicle traffic (MVA) (0.788; 95% CI, 0.775-0.801) and cutting or piercing (0.746; 95% CI, 0.701-0.791). Deceased patients were accurately identified by ISS 65.2% in injury by machinery, 47.7% in injury involving MVA, 39.7% in injury by firearm and 31.4% in injury by assault. After adjusting for confounders, the multivariate models in which ISS was the main independent factor performed best in predicting mortality from firearm and machinery mechanism of injuries. Although the ROC curve analysis demonstrated a moderate or high discriminatory ability to identify deceased patients in 6 out of twelve mechanisms, and the multivariate analysis revealed that ISS was a significant predictor of mortality in 9 out of 12 injury mechanisms, the sensitivities of all logistic regression models were poor. The ISS ≥ 16 threshold alone therefore should not be used to identify patients with high-mortality risk. The mortality risk assessment should be done individually and be based on clinical evaluation.

Trauma in elderly patients: a study of prevalence, comorbidities and gender differences

AIM

Trauma, in geriatric patients, increases with age, and is a leading cause of disability and institutionalization, resulting in morbidity and mortality. The aim of our study was to analyse the prevalence of trauma, the related risk factors, mortality and sex differences in the prevalence in a geriatric population.

PATIENTS AND METHOD

We observed 4,554 patients (≥65 years) with home injuries or car accidents. Patients were evaluated with ISS (Injury Severity Score) and major trauma with ATLS (Advanced Trauma Life Support). The instrumental investigation was in the first instance, targeted X-Ray or whole-body CT.

RESULTS

In over four years of study we treated 4,554 geriatric: 2,809 females and 1,745 Males. When the type of trauma was analysed the most common was head injury, followed by fractures of lower and upper limbs. In our experience hospitalization mainly involved patients over 80. In all patients mortality during assessment was 0.06%.

DISCUSSION

The geriatric patient is often defined as a "frail elderly", for the presence of a greater "injury sensitivity". This is due to the simultaneous presence of comorbidity, progressive loss of full autonomy and exposure to a high risk of traumatic events. Optimal management of the trauma patient can considerable reduce mortality and morbidity.

CONCLUSIONS

Falls and injuries in geriatric age are more frequent in women than in men. Among typical elder comorbidities, osteoporosis certainly causes a female preponderance in the prevalence of fractures. Our discharge data demonstrate that disability, which requires transfer to health care institutions, has a greater effect on women than men.

Lesiones graves y moderadas por accidentes de tránsito en mayores de 60 años. Medellín, Colombia

Introducción. Cada día, 3 400 personas mueren en el mundo por un accidente de tránsito (AT); miles sufren lesiones o adquieren una discapacidad cada año por la misma causa. En Colombia, en 2016 se registró una tasa de 92.8 heridos y 14.9 muertes por cada 100 000 habitantes.Objetivo. Describir las características de los AT y el entorno de su atención en mayores de 60 años con lesiones moderadas o graves en Medellín, Colombia, durante el periodo 2015-2016.Materiales y métodos. Estudio descriptivo de las características de personas mayores de 60 años con lesiones moderadas y graves después de un AT.Resultados. Se evaluaron 247 personas, 93.1% con lesiones moderadas; el 94.1% de las lesiones graves ocurrieron cuando se atropelló un peatón. En 60.7% de los AT una moto estuvo involucrada. El puntaje global del WHODAS-II fue de 40.6 y los dominios de funcionamiento más afectados fueron actividades domésticas, actividades fuera de la casa y movilidad; en cuanto a la calidad de vida, se afectó la función física, el desempeño físico y el cambio en salud.Conclusión. Los mayores de 60 años con lesiones por AT fueron, en su mayoría, peatones atropellados por motocicletas. El AT afectó la calidad de vida y el funcionamiento de los pacientes.

Survival and health related quality of life after severe trauma - a 15 years follow up study

INTRODUCTION

As the primary treatment of patients with severe trauma continues to improve, increasing interest has been directed towards long-term survival and Health Related Quality of Life (HRQoL). In trauma patients, there are few studies describing long-term outcome using tools specifically directed at HRQoL.

HYPOTHESIS

HRQoL measured with EQ-5D is significantly reduced compared to the Danish norm score 15 years after severe injury.

MATERIALS AND METHODS

All patients more than 18 years of age, admitted to a level 1 trauma center from March 1996 to September 1997 were prospectively included and scored with Injury Severity Score (ISS). Survival status was recorded in May 2012 and EQ-5D questionnaires were sent out.

RESULTS

95 of the original 154 trauma patients were eligible for participation. The response rate was 66%. The average EQ-5D index score in the trauma population was significantly reduced compared to the index score in the Danish norm population (P=0.00, one-sample t-test). In addition, ISS is associated with HRQoL and ISS≥16 predicts poorer HRQoL.

CONCLUSION

EQ-5D is significantly reduced 15years after severe trauma High ISS was associated with low HRQoL. Knowledge of the distribution and predictors of long-term disability can be used to develop more efficient prevention policies and to improve trauma care in general.

A Changing of the Abbreviated Injury Scale that Improves Accuracy and Simplifies Scoring

Objective

We present here a changing of the abbreviated injury scale (AIS). It is called the changed injury severity score (CISS), and significantly outperforms the venerable but dated the injury severity score (ISS) and the new injury severity score (NISS) as a predictor of mortality.

Methods

The CISS is defined as a change of AIS values by raising each AIS severity score (1-6) by a power of 4.12 divided by 30.33 and then summing the three most severe (i.e. highest AIS) regardless of body regions. CISS values were calculated for every patient in two large independent data sets: 3455, 3900 patients treated during a five-year period at the class A grade III comprehensive hospitals in Affiliated Hospital of Hangzhou Normal University (Hangzhou) and Zhejiang Provincial People's Hospital (Zhejiang). The power of CISS to predict morality was then compared with previously calculated NISS values of the same group patients in the two hospitals.

Results

We found CISS was more accurate than NISS to predict the survival. The receiver operating characteristic (ROC) of NISS and CISS in Hangzhou were 0.919 and 0.937 respectively (p=0.026), whereas for Zhejiang were 0.917 and 0.940 respectively (p=0.022). Moreover, CISS provided a better fit throughout its entire range of prediction. Hosmer-Lemeshow (H-L) statistic for NISS and CISS in Hangzhou were 24.00 (p=0.002) and 19.38 (p=0.007), whereas in Zhejiang were 22.70 (p=0.001) and 18.43 (p=0.005) respectively.

Conclusions

CISS is a modified version of NISS/ISS with better statistical property and can be considered in trauma research.

Comparison of the new Exponential Injury Severity Score with the Injury Severity Score and the New Injury Severity Score in trauma patients: A cross-sectional study

Objective

To compare Exponential Injury Severity Score (EISS) with Injury Severity Score (ISS) and New Injury Severity Score (NISS) in terms of their predictive capability of the outcomes and medical expenses of hospitalized adult trauma patients.

Setting

This study was based at a level I trauma center in Taiwan.

Methods

Data for 17,855 adult patients hospitalized from January 1, 2009 to December 31, 2015 were retrieved from the Trauma Registry System. The primary outcome was in-hospital mortality. Secondary outcomes were the hospital length of stay (LOS), intensive care unit (ICU) admission rate, ICU LOS, and medical expenses. Chi-square tests were used for categorical variables to determine the significance of the associations between the predictor and outcome variables. Student t-tests were applied to analyze normally distributed data for continuous variables, while Mann-Whitney U tests were used to compare non-normally distributed data.

Results

According to the survival rate-to-severity score relationship curve, we grouped all adult trauma patients based on EISS scores of ≥ 27, 9–26, and < 9. Significantly higher mortality rates were noted in patients with EISS ≥ 27 and those with EISS of 9–26 when compared to patients with EISS < 9; this finding concurred to the findings for groups classified by the ISS and NISS with the cut-off points set between 25 and 16. The hospital LOS, ICU admission rates, and medical expenses for patients with EISS ≥ 27 and patients with EISS of 9–26 were also significantly longer and higher than that of patients with EISS < 9. When comparing the demographics and detailed medical expenses of very severely injured adult trauma patients classified according to ISS, NISS, and EISS, patients with ISS ≥ 25 and NISS ≥ 25 both had significantly lower mortality rates, lower ICU admission rates, and shorter ICU LOS compared to patients with EISS ≥ 27.

Conclusions

EISS 9 and 27 can serve as two cut-off points regarding injury severity, and patients with EISS ≥ 27 have the greatest injury severity. Additionally, these patients have the highest mortality rate, the highest ICU admission rate, and the longest ICU LOS compared to those with ISS ≥ 25 and NISS ≥ 25, suggesting that patients with EISS ≥ 27 have the worst outcome.

Performance of new adjustments to the TRISS equation model in developed and developing countries

BACKGROUND

The Trauma and Injury Severity Score (TRISS) has been criticized for being based on data from the USA and Canada-high-income countries-and therefore, it may not be applicable to low-income and middle-income countries. The present study evaluated the accuracy of three adjustments to the TRISS equation model (NTRISS-like; TRISS SpO2; NTRISS-like SpO2) in a high-income and a middle-income country to compare their performance when derived and applied to different groups.

METHODS

This was a retrospective study of trauma patients admitted to two institutions: a university medical center in São Paulo, Brazil (a middle-income country), and a level 1 university trauma center in San Diego, USA (a high-income country). Patients were admitted between January 1, 2006, and December 31, 2010. The subjects were 2416 patients from Brazil and 8172 patients from the USA. All equations had adjusted coefficients for São Paulo and San Diego and for blunt and penetrating trauma. Receiver operating characteristic (ROC) curves were used to evaluate performance of the models.

RESULTS

Regardless of the population where the equation was generated, it performed better when applied to patients in the USA (AUC from 0.911 to 0.982) compared to patients in Brazil (AUC from 0.840 to 0.852). When the severity was considered and homogenized, the performance of equations were similar to both application in the USA and Brazil.

CONCLUSIONS

Survival probability models showed better performance when applied in data collected in the high-income countries (HIC) regardless the country they were derived. The severity is an important factor to consider when using non-adjusted survival probability models for the local population. Adjusted models for severely traumatized patients better predict survival probability in less severely traumatized populations. Other factors besides physiological and anatomical data may impact final outcomes and should be identified in each environment if they are to be used in the development of the trauma care performance improvement process in middle-income countries.

Systematic review and need assessment of pediatric trauma outcome benchmarking tools for low-resource settings

INTRODUCTION

Trauma is a leading cause of mortality and disability in children worldwide. The World Health Organization reports that 95% of all childhood injury deaths occur in Low-Middle-Income Countries (LMIC). Injury scores have been developed to facilitate risk stratification, clinical decision making, and research. Trauma registries in LMIC depend on adapted trauma scores that do not rely on investigations that require unavailable material or human resources. We sought to review and assess the existing trauma scores used in pediatric patients. Our objective is to determine their wideness of use, validity, setting of use, outcome measures, and criticisms. We believe that there is a need for an adapted trauma score developed specifically for pediatric patients in low-resource settings.

MATERIALS AND METHODS

A systematic review of the literature was conducted to identify and compare existing injury scores used in pediatric patients. We constructed a search strategy in collaboration with a senior hospital librarian. Multiple databases were searched, including Embase, Medline, and the Cochrane Central Register of Controlled Trials. Articles were selected based on predefined inclusion criteria by two reviewers and underwent qualitative analysis.

RESULTS

The scores identified are suboptimal for use in pediatric patients in low-resource settings due to various factors, including reliance on precise anatomic diagnosis, physiologic parameters maladapted to pediatric patients, or laboratory data with inconsistent accessibility in LMIC.

CONCLUSION

An important gap exists in our ability to simply and reliably estimate injury severity in pediatric patients and predict their associated probability of outcomes in settings, where resources are limited. An ideal score should be easy to calculate using point-of-care data that are readily available in LMIC, and can be easily adapted to the specific physiologic variations of different age groups.

Validation of trauma scales: ISS, NISS, RTS and TRISS for predicting mortality in a Colombian population

BACKGROUND

Our purpose was to validate the performance of the ISS, NISS, RTS and TRISS scales as predictors of mortality in a population of trauma patients in a Latin American setting.

MATERIALS AND METHODS

Subjects older than 15 years with diagnosis of trauma, lesions in two or more body areas according to the AIS and whose initial attention was at the hospital in the first 24 h were included. The main outcome was inpatient mortality. Secondary outcomes were admission to the intensive care unit, requirement of mechanical ventilation and length of stay. A logistic regression model for hospital mortality was fitted with each of the scales as an independent variable, and its predictive accuracy was evaluated through discrimination and calibration statistics.

RESULTS

Between January 2007 and July 2015, 4085 subjects were enrolled in the study. 84.2% (n = 3442) were male, the mean age was 36 years (SD = 16), and the most common trauma mechanism was blunt type (80.1%; n = 3273). The medians of ISS, NISS, TRISS and RTS were: 14 (IQR = 10-21), 17 (IQR = 11-27), 4.21 (IQR = 2.95-5.05) and 7.84 (IQR = 6.90-7.84), respectively. Mortality was 9.3%, and the discrimination for ISS, NISS, TRISS and RTS was: AUC 0.85, 0.89, 0.86 and 0.92, respectively. No one scale had appropriate calibration.

CONCLUSION

Determining the severity of trauma is an essential tool to guide treatment and establish the necessary resources for attention. In a Colombian population from a capital city, trauma scales have adequate performance for the prediction of mortality in patients with trauma.

Comparison of the Ability to Predict Mortality between the Injury Severity Score and the New Injury Severity Score: A Meta-Analysis

Background: Description of the anatomical severity of injuries in trauma patients is important. While the Injury Severity Score has been regarded as the “gold standard” since its creation, several studies have indicated that the New Injury Severity Score is better. Therefore, we aimed to systematically evaluate and compare the accuracy of the Injury Severity Score and the New Injury Severity Score in predicting mortality. Methods: Two researchers independently searched the PubMed, Embase, and Web of Science databases and included studies from which the exact number of true-positive, false-positive, false-negative, and true-negative results could be extracted. Quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies checklist criteria. The meta-analysis was performed using Meta-DiSc. Meta-regression, subgroup analyses, and sensitivity analyses were conducted to determine the source(s) of heterogeneity and factor(s) affecting the accuracy of the New Injury Severity Score and the Injury Severity Score in predicting mortality. Results: The heterogeneity of the 11 relevant studies (total n = 11,866) was high (I² > 80%). The meta-analysis using a random-effects model resulted in sensitivity of 0.64, specificity of 0.93, positive likelihood ratio of 5.11, negative likelihood ratio of 0.27, diagnostic odds ratio of 27.75, and area under the summary receiver operator characteristic curve of 0.9009 for the Injury Severity Score; and sensitivity of 0.71, specificity of 0.87, positive likelihood ratio of 5.22, negative likelihood ratio of 0.20, diagnostic odds ratio of 24.74, and area under the summary receiver operating characteristic curve of 0.9095 for the New Injury Severity Score. Conclusion: The New Injury Severity Score and the Injury Severity Score have similar abilities in predicting mortality. Further research is required to determine the appropriate use of the Injury Severity Score or the New Injury Severity Score based on specific patient condition and trauma type.

Mortality in trauma patients with active arterial bleeding managed by embolization or surgical packing: An observational cohort study of 66 patients

Objective:

Exsanguination due to coagulopathy and vascular injury is a common cause of death among trauma patients. Arterial injury can be treated either by angiography and embolization or by explorative laparotomy and surgical packing. The purpose of this study was to compare 30-day mortality and blood product consumption in trauma patients with active arterial haemorrhage in the abdominal and/or pelvic region treated with either angiography and embolization or explorative laparotomy and surgical packing.

Material and Methods:

From January 1^st 2006 to December 31^st 2011 2,173 patients with an ISS of >9 were admitted to the Trauma Centre of Copenhagen University Hospital, Rigshospitalet, Denmark. Of these, 66 patients met the inclusion criteria: age above 15 years and active arterial haemorrhage from the abdominal and/or pelvic region verified by a CT scan at admission. Gender, age, initial oxygen saturation, pulse rate and respiratory rate, mechanism of injury, ISS, Probability of Survival, treatment modality, 30-day mortality and number and type of blood products applied were retrieved from the TARN database, patient records and the Danish Civil Registration System.

Results:

Thirty-one patients received angiography and embolization, and 35 patients underwent exploratory laparotomy and surgical packing. Gender, age, initial oxygen saturation, pulse rate and respiratory rate, ISS and Probability of Survival were comparable in the two groups.

Conclusion:

A significant increased risk of 30-day mortality (P = 0.04) was found in patients with active bleeding treated with explorative laparotomy and surgical packing compared to angiography and embolization when data was adjusted for age and ISS. No statistical significant difference (P > 0.05) was found in number of transfused blood products applied in the two groups of patients.

New Injury Severity Score is a better predictor of mortality for blunt trauma patients than the Injury Severity Score

BACKGROUND

Trauma-related mortality depends on injury severity. Several trauma scores are used to evaluate injury severity. We compared the Injury Severity Score (ISS) and the New Injury Severity Score (NISS) in terms of predicting mortality among hospitalized blunt trauma patients.

METHODS

The data of Al-Ain Hospital Trauma Registry were prospectively collected over 3 years. Data of blunt trauma patients were then analyzed retrospectively. Univariate analysis was used to compare patients who died with those who survived. Sex, age, mechanism of injury, heart rate, systolic blood pressure (SBP), and Glasgow Coma Score (GSC) on arrival at the hospital, ISS, and NISS were studied. Significant factors were then entered into a direct likelihood ratio logistic regression model.

RESULTS

Of 2,573 patients in the registry, 2,115 (82.2 %) suffered blunt trauma at a mean (SD) age of 32 (15.3) years. Among them, 1,838 (87 %) were male. Main mechanisms of injury were road traffic collision (vehicle occupants) (32.8 %) and falling from a height (22.4 %). Fifty patients (2.4 %) died. Univariate analysis showed that GCS and SBP at hospital arrival, ISS, NISS, and mechanism of injury significantly affected mortality. Logistic regression model showed that mortality was significantly increased by low GCS (p < 0.0001), high NISS (p < 0.0001), and low SBP (p = 0.006) at hospital arrival.

CONCLUSIONS

Mortality of blunt trauma in the UAE is significantly affected by high NISS, low GCS, and hypotension. NISS is better than ISS for predicting mortality of blunt trauma patients and may replace it.

Denver ED Trauma Organ Failure Score outperforms traditional methods of risk stratification in trauma

BACKGROUND

Early identification of trauma patients at risk for inhospital mortality may facilitate goal-directed resuscitation and secondary triage to improve outcomes. The objective of this study was to compare prognostic accuracies of the Denver Emergency Department (ED) Trauma Organ Failure (TOF) Score, ED Sequential Organ Failure Assessment (SOFA) score, and ED base deficit and ED lactate for inhospital mortality in adult trauma patients.

METHODS

Consecutive adult trauma patients from 2005 to 2008 from the Denver Health Trauma Registry were included. Prognostic accuracies of the Denver ED TOF Score, ED SOFA score, ED base deficit, and ED lactate for inhospital mortality were evaluated with receiver operating characteristic curves.

RESULTS

Of the 4355 patients, the median age was 37 years (interquartile range [IQR], 26-51 years), median Injury Severity Score was 9 (IQR, 4-16), and 81% had blunt mechanisms. In addition, 38% (1670 patients) were admitted to the intensive care unit with a median intensive care unit length of stay of 2.5 days (IQR, 1-8 days), and 3% (138 patients) died. The areas under the receiver operating characteristic curves for the Denver ED TOF, ED lactate, ED base deficit, and ED SOFA were 0.94 (95% confidence interval [CI], 0.94-0.96), 0.88 (95% CI, 0.85-0.91), 0.82 (95% CI, 0.78-0.86), and 0.78 (95% CI, 0.73-0.82), respectively.

CONCLUSIONS

The Denver ED TOF Score more accurately predicts inhospital mortality in adult trauma patients compared to the ED SOFA score, ED base deficit, or ED lactate. The Denver ED TOF Score may help identify patients early who are at risk for mortality, allowing for targeted resuscitation and secondary triage to improve outcomes.

Tangent function transformation of the Abbreviated Injury Scale improves accuracy and simplifies scoring

INTRODUCTION

The Injury Severity Score (ISS) and the New Injury Severity Score (NISS) are widely used for anatomic severity assessments after trauma. We present here the Tangent Injury Severity Score (TISS), which transforms the Abbreviated Injury Scale (AIS) as a predictor of mortality.

MATERIAL AND METHODS

The TISS is defined as the sum of the tangent function of AIS/6 to the power 3.04 multiplied by 18.67 of a patient's three most severe AIS injuries regardless of body regions. TISS values were calculated for every patient in two large independent data sets: 3,908 and 4,171 patients treated during a 6-year period at level-3 first-class comprehensive hospitals: the Affiliated Hospital of Hangzhou Normal University and Fengtian Hospital Affiliated to Shenyang Medical College, China. The power of TISS to predict mortality was compared with previously calculated NISS values for the same patients in each data set.

RESULTS

The TISS is more predictive of survival than NISS (Hangzhou: receiver operating characteristic (ROC): NISS = 0.929, TISS = 0.949; p = 0.002; Shenyang: ROC: NISS = 0.924, TISS = 0.942; p = 0.008). Moreover, TISS provides a better fit throughout its entire range of prediction (Hosmer Lemeshow statistic for Hangzhou NISS = 29.71; p < 0.001, TISS = 19.59; p = 0.003; Hosmer Lemeshow statistic for Shenyang NISS = 33.49; p < 0.001, TISS = 21.19; p = 0.002).

CONCLUSIONS

The TISS shows more accurate prediction of prognosis and a linear relation to mortality. The TISS might be a better injury scoring tool with simple computation.

Utilisation of Blood Components in Trauma Surgery: A Single-Centre, Retrospective Analysis before and after the Implementation of an Educative PBM Initiative

BACKGROUND

The aim of our single-centre retrospective study presented here is to further analyse the utilisation of allogeneic blood components within a 5-year observation period (2009-2013) in trauma surgery (15,457 patients) under the measures of an educational patient blood management (PBM) initiative.

METHODS

After the implementation of the PBM initiative in January 2012, the Institute of Transfusion Medicine und Transplantation Immunology educates surgeons and nurses at the Department of Trauma Surgery to avoid unnecessary blood transfusions. A standardised reporting system was used to document the utilisation of blood components carefully for the most frequent diagnoses and surgical interventions in trauma surgery. These measures served as basis for the implementation of an interdisciplinary systematic exchange of information to foster decision-making processes in favour of patient blood management.

RESULTS

Since January 2012, the proportion of patients who received a transfusion as well as the number of transfused red blood cell (RBC) (7.3%/6.4%; p = 0.02), fresh frozen plasma (FFP) (1.7%/1.3%; p < 0.05) and platelet (PLT) (1.0%/0.5%; p < 0.001) units were reduced as a result of our PBM initiative. However, among the transfused patients, the number of administered RBC, FFP and PLT units did not decrease significantly. Overall, patients who did not receive transfusions were younger than transfused patients (p = 0.001). The subgroup with the highest probability of blood transfusion administered included patients with intensive care and long-term ventilation (before/after implementation of PBM: RBC 81.5%/75.9%; FFP 33.3%/20.4%; PLT 24.1%/13.0%). Only a total of 60 patients of 531 patients suffering multiple traumas were massively transfused (before/after implementation of PBM: RBC 55.6%/49.8%; FFP 28.4%/20.4%; PLT 17.6%/8.9%).

CONCLUSION

According to our educational PBM initiative, at least the proportion of trauma patients who received allogeneic blood transfusions could be reduced significantly. However, in case of blood transfusions, the total consumption of RBC, FFP and PLT units remained stable in both time periods. This phenomenon might indicate that the actual need of blood transfusions rather depends on the severity of trauma-related blood loss, the coagulopathy rates or the complexity of the surgical intervention which mainly determines the intra-operative blood loss. Taken together, educational training sessions and systematic reporting systems are suitable measures to avoid unnecessary allogeneic blood transfusions and to continuously improve their restrictive application.

How to define severely injured patients? -- an Injury Severity Score (ISS) based approach alone is not sufficient

INTRODUCTION

Multiple injured patients, polytrauma or severely injured patients are terms used as synonyms in international literature describing injured patients with a high risk of mortality and cost consuming therapeutic demands. In order to advance the definition of these terms, we analysed a large trauma registry. In detail, we compared critically ill trauma patients first specified on a pure anatomical base according to the ISS or NISS, second in the original "polytrauma definition" with two body regions affected and finally all of them combined with a physiological component.

PATIENTS AND METHODS

Records that were collected in the TraumaRegister DGU(®) of the German Trauma Society (Deutsche Gesellschaft für Unfallchirurgie, DGU) between 1993 and 2011 (92,479 patients) were considered for this study. All patients with primary admission from scene with a minimum hospital stay of 48 h and an Injury Severity Score (ISS)≥ 16 were included. Pre-hospital and early admission data were used to determine physiological risk factors and calculate individual risk of death using the Revised Injury Severity Classification (RISC).

RESULTS

45,350 patients met inclusion criteria. The overall hospital mortality rate was 20.4%. The predicted mortality according to the RISC-Score was 21.6%. 36,897 patients (81.4%) had injuries in several body regions. The prevalence of the five physiological risk factors varied between 17% (high age) and 34% (unconsciousness). There were 17,617 patients (38.8%) without any risk factor present on admission, while 30.6% (n=13,890) of the patients had one and 30.5% (n=13,843) had two or more factors present. Patients with ISS ≥ 16 but no physiological risk factor present had a very low mortality rate of 3.1% (542 of 17,617). With an increasing number of physiological factors there was an almost linear increase in mortality up to an 86% rate in patients with all five factors present. The 'polytrauma' definition of Butcher and colleagues with AIS ≥ 3 in at least two different body regions would apply to only 56.2% of patients in the present group with ISS ≥ 16. The mortality in this subgroup is only marginally higher (21.8%; 5559 of 25,494) than in the group of patients with only one severely affected body region (18.5%; 3675 of 19,875).

CONCLUSIONS

In our opinion the principle of sharpening an anatomically based definition by a defined physiological problem will help to specify the really critically ill trauma patients.

Norwegian survival prediction model in trauma: modelling effects of anatomic injury, acute physiology, age, and co-morbidity

INTRODUCTION

Anatomic injury, physiological derangement, age, and injury mechanism are well-founded predictors of trauma outcome. We aimed to develop and validate the first Scandinavian survival prediction model for trauma.

METHODS

Eligible were patients admitted to Oslo University Hospital Ullevål within 24 h after injury with Injury Severity Score ≥ 10, proximal penetrating injuries or received by a trauma team. The derivation dataset comprised 5363 patients (August 2000 to July 2006); the validation dataset comprised 2517 patients (August 2006 to July 2008). Exclusion because of missing data was < 1%. Outcome was 30-day mortality. Logistic regression analysis incorporated fractional polynomial modelling and interaction effects. Model validation included a calibration plot, Hosmer-Lemeshow test and receiver operating characteristic (ROC) curves.

RESULTS

The new survival prediction model included the anatomic New Injury Severity Score (NISS), Triage Revised Trauma Score (T-RTS, comprising Glascow Coma Scale score, respiratory rate, and systolic blood pressure), age, pre-injury co-morbidity scored according to the American Society of Anesthesiologists Physical Status Classification System (ASA-PS), and an interaction term. Fractional polynomial analysis supported treating NISS and T-RTS as linear functions and age as cubic. Model discrimination between survivors and non-survivors was excellent. Area (95% confidence interval) under the ROC curve was 0.966 (0.959-0.972) in the derivation and 0.946 (0.930-0.962) in the validation dataset. Overall, low mortality and skewed survival probability distribution invalidated model calibration using the Hosmer-Lemeshow test.

CONCLUSIONS

The Norwegian survival prediction model in trauma (NORMIT) is a promising alternative to existing prediction models. External validation of the model in other trauma populations is warranted.

ISS groups: are we speaking the same language?

BACKGROUND

Despite ISS being a widely accepted tool for measuring injury severity, many researchers and practitioners use different partition of ISS into severity groups. The lack of uniformity in ISS use inhibits proper comparisons between different studies. Creation of ISS group boundaries based on single AIS value squares and their sums was proposed in 1988 during Major Trauma Study (MTOS) in the USA, but was not validated by analysis of large databases.

METHODS

A validation study analysing 316,944 patients in the Israeli National Trauma registry (INTR) and 249,150 patients in the American National Trauma Data Bases (NTDB). A binary algorithm (Classification and Regression Trees (CART)) was used to detect the most significantly different ISS groups and was also applied to original MTOS data.

RESULTS

The division of ISS into groups by the CART algorithm was identical in both Trauma Registries and very similar to original division in the MTOS. For most samples, the recommended groups are 1-8, 9-14, 16-24 and 25-75, while in very large samples or in studies specifically targeting critical patients there is a possibility to divide the last group into 25-48 and 50-75 groups, with an option for further division into 50-66 and 75 groups.

CONCLUSIONS

Using a statistical analysis of two very large databases of trauma patients, we have found that partitioning of ISS into groups based on their association with patient mortality enables us to establish clear cut-off points for these groups. We propose that the suggested partition of ISS into severity groups would be adopted as a standard in order to have a common language when discussing injury severity.

Physiologic, demographic and mechanistic factors predicting New Injury Severity Score (NISS) in motor vehicle accident victims

BACKGROUND

Current literature on motor vehicle accidents (MVAs) has few reports regarding field factors that predict the degree of injury. Also, studies of mechanistic factors rarely consider concurrent predictive effects of on-scene patient physiology. The New Injury Severity Score (NISS) has previously been found to correlate with mortality, need for ICU admission, length of hospital stay, and functional recovery after trauma. To potentially increase future precision of trauma triage, we assessed how the NISS is associated with physiologic, demographic and mechanistic variables from the accident site.

METHODS

Using mixed-model linear regression analyses, we explored the association between NISS and pre-hospital Glasgow Coma Scale (GCS) score, Revised Trauma Score (RTS) categories of respiratory rate (RR) and systolic blood pressure (SBP), gender, age, subject position in the vehicle, seatbelt use, airbag deployment, and the estimated squared change in vehicle velocity on impact ((Δv)(2)). Missing values were handled with multiple imputation.

RESULTS

We included 190 accidents with 353 dead or injured subjects (mean NISS 17, median NISS 8, IQR 1-27). For the 307 subjects in front-impact MVAs, the mean increase in NISS was -2.58 per GCS point, -2.52 per RR category level, -2.77 per SBP category level, -1.08 for male gender, 0.18 per year of age, 4.98 for driver vs. rear passengers, 4.83 for no seatbelt use, 13.52 for indeterminable seatbelt use, 5.07 for no airbag deployment, and 0.0003 per (km/h)(2) velocity change (all p<0.002).

CONCLUSION

This study in victims of MVAs demonstrated that injury severity (NISS) was concurrently and independently predicted by poor pre-hospital physiologic status, increasing age and female gender, and several mechanistic measures of localised and generalised trauma energy. Our findings underscore the need for precise information from the site of trauma, to reduce undertriage, target diagnostic efforts, and anticipate need for high-level care and rehabilitative resources.

The exponential function transforms the Abbreviated Injury Scale, which both improves accuracy and simplifies scoring

PURPOSE

We present here the exponential function which transforms the Abbreviated Injury Scale (AIS). It is called the Exponential Injury Severity Score (EISS), and significantly outperforms the venerable but dated New Injury Severity Score (NISS) and Injury Severity Score (ISS) as a predictor of mortality.

METHODS

The EISS is defined as a change of AIS values by raising each AIS severity score (1-6) by 3 taking a power of AIS minus 2 and then summing the three most severe injuries (i.e., highest AIS), regardless of body regions. EISS values were calculated for every patient in two large independent data sets: 3,911 and 4,129 patients treated during a 6-year period at the Class A tertiary hospitals in China. The power of the EISS to predict mortality was then compared with previously calculated NISS values for the same patients in each of the two data sets.

RESULTS

We found that the EISS is more predictive of survival [Zhejiang: area under the receiver operating characteristic curve (AUC): NISS = 0.932, EISS = 0.949, P = 0.0115; Liaoning: AUC: NISS = 0.924, EISS = 0.942, P = 0.0139]. Moreover, the EISS provides a better fit throughout its entire range of prediction (Hosmer-Lemeshow statistic for Zhejiang: NISS = 21.86, P = 0.0027, EISS = 13.52, P = 0.0604; Liaoning: NISS = 23.27, P = 0.0015, EISS = 15.55, P = 0.0164).

CONCLUSIONS

The EISS may be used as the standard summary measure of human trauma.

A population based study of hospitalised seriously injured in a region of Northern Italy

Background

Injury is a public health problem in terms of mortality, morbidity and disability. The implementation of a regionalised trauma system has been proved to significantly reduce the social impact of severe trauma on population. A population-based registry may be useful to obtain reliable epidemiologic data.

Aim

To perform an exhaustive analysis of severe trauma patients hospitalised in Lombardia, a region of northern Italy.

Materials and methods

The regional Hospital Discharge Registry (HDR) was used to retrieve data of all patients who suffered from serious injuries from 2008 to 2010. ICD9-CM codes of discharge diagnoses were analysed and patients coded from 800.0 to 939.9 or from 950.0 to 959.9 have been retrieved. Femur fractures in elderly and patients with length of hospital stay less than 2 days were excluded. Patients have been considered seriously injured if discharged dead or any of followings: admission or transit in ICU, need of mechanical ventilation, tracheotomy, invasive hemodynamic monitoring. Average reimbursement based on DRG has been evaluated.

Statistics

Student’s t test, ANOVA for continuous data, chi-square test for categorical data were used, and a p value less than 0.05 was considered significant.

Results

The severely injured patients hospitalised in Lombardia in three years were 11704, 391 per million per year. Overall mortality was 24.17% and increased with age. Males aging from 18 to 64 years had more occupational injuries, trauma on the road and violence by others. Females were more susceptible to domestic injuries and self inflicted violence, mostly in older ages. Acute mortality was higher after traffic accidents, while late mortality was increased in domestic trauma. Pediatric cases were unusual. A significant increase (+10.18%) in domestic trauma, with a concomitant decrease (-17.76%) in road-related accidents was observed in the three years study period. Reimbursement paid to hospitals for seriously injured was insufficient with regard to estimated costs of care.

Conclusion

Serious injury requiring hospitalisation in Lombardia is still an healthcare problem, with a trend toward a decrease of traffic accidents, increase in domestic trauma and involvement of older people. These results may help to plan a new regionalised Trauma System.

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.

Validating scores: a good business for a trauma register

Acute hemorrhage after life-threatening injury is still one of the main killers after trauma. The article by Brockamp and colleagues presents a good overview of recent scores for estimation of blood loss and transfusion requirement.

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.

Calculating trauma triage precision: effects of different definitions of major trauma

BACKGROUND

Triage is the process of classifying patients according to injury severity and determining the priority for further treatment. Although the term "major trauma" represents the reference against which over- and undertriage rates are calculated, its definition is inconsistent in the current literature. This study aimed to investigate the effects of different definitions of major trauma on the calculation of perceived over- and undertriage rates in a Norwegian trauma cohort.

METHODS

We performed a retrospective analysis of patients included in the trauma registry of a primary, referral trauma centre. Two "traditional" definitions were developed based on anatomical injury severity scores (ISS >15 and NISS >15), one "extended" definition was based on outcome (30-day mortality) and mechanism of injury (proximal penetrating injury), one "extensive" definition was based on the "extended" definition and on ICU resource consumption (admitted to the ICU for >2 days and/or transferred intubated out of the hospital in ≤2 days), and an additional four definitions were based on combinations of the first four.

RESULTS

There were no significant differences in the perceived under- and overtriage rates between the two "traditional" definitions (NISS >15 and ISS >15). Adding "extended" and "extensive" to the "traditional" definitions also did not significantly alter perceived under- and overtriage. Defining major trauma only in terms of the mechanism of injury and mortality, with or without ICU resource consumption (the "extended" and "extensive" groups), drastically increased the perceived overtriage rates.

CONCLUSION

Although the proportion of patients who were defined as having sustained major trauma increased when NISS-based definitions were substituted for ISS-based definitions, the outcomes of the triage precision calculations did not differ significantly between the two scales. Additionally, expanding the purely anatomic definition of major trauma by including proximal penetrating injury, 30-day mortality, ICU LOS greater than 2 days and transferred intubated out of the hospital at ≤2 days did not significantly influence the perceived triage precision. We recommend that triage precision calculations should include anatomical injury scaling according to NISS. To further enhance comparability of trauma triage calculations, researchers should establish a consensus on a uniform definition of major trauma.

The role of the New Trauma and Injury Severity Score (NTRISS) for survival prediction

The objective of this study was to verify if replacing the Injury Severity Score (ISS) by the New Injury Severity Score (NISS) in the original Trauma and Injury Severity Score (TRISS) form would improve the survival rate estimation. This retrospective study was performed in a level I trauma center during one year. ROC curve was used to identify the best indicator (TRISS or NTRISS) for survival probability prediction. Participants were 533 victims, with a mean age of 38±16 years. There was predominance of motor vehicle accidents (61.9%). External injuries were more frequent (63.0%), followed by head/neck injuries (55.5%). Survival rate was 76.9%. There is predominance of ISS scores ranging from 9-15 (40.0%), and NISS scores ranging from 16-24 (25.5%). Survival probability equal to or greater than 75.0% was obtained for 83.4% of the victims according to TRISS, and for 78.4% according to NTRISS. The new version (NTRISS) is better than TRISS for survival prediction in trauma patients.

Injury severity scoring systems: a review of application to practice

AIM

This study reviews the historical development of injury severity scoring systems and their application to clinical practice.

BACKGROUND

A variety of injury severity scoring systems have been developed and applied since more than four decades. It is increasingly important for nurses to be familiar with these scoring systems, their strengths and weaknesses, and their applications to nursing practice.

DESIGN

Systematic literature review.

METHODS

The injury severity scoring systems developed from the 1970s to 2011 were identified via electronic database searches, footnote chasing and contact with clinical experts. The most frequently used scoring systems in the literature were classified according to the criteria used in each scoring system.

CONCLUSIONS

All injury severity scoring systems are valuable but have certain problems. A universal scoring system applicable for various purposes appears difficult to achieve. However, the understanding and proper use of scoring systems will allow us to perform critical evaluations and continual refinement of trauma management.

RELEVANCE TO CLINICAL PRACTICE

As nurses and researchers, it is critical that we should know the application of these injury severity scoring systems to ensure their quality and appropriate utilization.

The counterintuitive effect of multiple injuries in severity scoring: a simple variable improves the predictive ability of NISS

Background

Injury scoring is important to formulate prognoses for trauma patients. Although scores based on empirical estimation allow for better prediction, those based on expert consensus, e.g. the New Injury Severity Score (NISS) are widely used. We describe how the addition of a variable quantifying the number of injuries improves the ability of NISS to predict mortality.

Methods

We analyzed 2488 injury cases included into the trauma registry of the Italian region Emilia-Romagna in 2006-2008 and assessed the ability of NISS alone, NISS plus number of injuries, and the maximum Abbreviated Injury Scale (AIS) to predict in-hospital mortality. Hierarchical logistic regression was used. We measured discrimination through the C statistics, and calibration through Hosmer-Lemeshow statistics, Akaike's information criterion (AIC) and calibration curves.

Results

The best discrimination and calibration resulted from the model with NISS plus number of injuries, followed by NISS alone and then by the maximum AIS (C statistics 0.775, 0.755, and 0.729, respectively; AIC 1602, 1635, and 1712, respectively). The predictive ability of all the models improved after inclusion of age, gender, mechanism of injury, and the motor component of Glasgow Coma Scale (C statistics 0.889, 0.898, and 0.901; AIC 1234, 1174, and 1167). The model with NISS plus number of injuries still showed the best performances, this time with borderline statistical significance.

Conclusions

In NISS, the same weight is assigned to the three worst injuries, although the contribution of the second and third to the probability of death is smaller than that of the worst one. An improvement of the predictive ability of NISS can be obtained adjusting for the number of injuries.

Factors associated with trauma center use for elderly patients with trauma: a statewide analysis, 1999-2008

OBJECTIVES

To estimate the likelihood of trauma center admission for injured elderly patients with trauma, determine trends in trauma center admissions, and identify factors associated with trauma center use for elderly patients with trauma.

DESIGN

Retrospective analysis.

SETTING

Acute care hospitals in California.

PATIENTS

All patients hospitalized for acute traumatic injuries during the period from January 1, 1999, to December 31, 2008 (n = 430,081). Patients who had scheduled admissions for nonacute or minor trauma were excluded.

MAIN OUTCOME MEASURE

Likelihood of admission to level I or II trauma center was calculated according to age categories after adjusting for patient and system factors.

RESULTS

Of 430,081 patients admitted to California acute care hospitals for trauma-related diagnoses, 27% were older than 65 years. After adjusting for demographic, clinical, and system factors, compared with trauma patients aged 18-25 years, the odds of admission to a trauma center decreased with increasing age; patients aged 26-45 years had lower odds (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.71-0.80) of being admitted to a trauma center for their injuries than did patients 46-65 years of age (OR, 0.57; 95% CI, 0.54-0.60), patients 66-85 years of age (OR, 0.35; 95% CI, 0.30-0.41), and patients older than 85 years (OR, 0.30; 95% CI, 0.25-0.36). Similar patterns were found when stratifying the analysis by trauma type and severity. Living more than 50 miles away from a trauma center (OR, 0.03; 95% CI, 0.01-0.06) and lack of county trauma center (OR, 0.17; 95% CI, 0.09-0.35) were also predictors of not receiving trauma care.

CONCLUSION

Age and likelihood of admission to a trauma center for injured patients were observed to be inversely proportional after controlling for other factors. System-level factors play a major role in determining which injured patients receive trauma care.

Trauma and Injury Severity Score (TRISS): is it time for variable re-categorisations and re-characterisations?

BACKGROUND

Despite its limitations, the Trauma and Injury Severity Score (TRISS) continues to be the most commonly used tool for benchmarking trauma outcome. Since its inception, considerable energy has been devoted to improving TRISS. However, there has been no investigation into the classification or characterisation of the TRISS variables. Using a major nationally representative database, this study aims to explore the adequacy of the existing TRISS model by investigating variable re-categorisations and alternative characterisations in a logistic model used to predict survival in adults after traumatic injury.

MATERIALS AND METHODS

Data were obtained from the National Trauma Data Bank National Sample Project (NSP). Each variable in the TRISS model was related to discharge status and various categorisations considered using weighted logistic regression. Categorisations were treated nominally,using a series of indicator variables. For each variable and classification level, the best category combination was ascertained using the Bayesian Information Criterion (BIC). All best 5-category classified TRISS variables were combined, as were all best 10-category classified TRISS variables, and their predictive performance assessed against two conventionally defined TRISS models on the unweighted NSP sample using area under the Receiver Operating Characteristic curve (AUC) and BIC statistics.

RESULTS

Overall, the weighted sample included 1,124,001 adults with injury events and known discharge status, of whom 1,061,709 (94.5%) were alive at discharge. When separately related to discharge status, each re-classified TRISS variable yielded a superior BIC statistic to its original specification. When investigating predictive performance, complete information was available for 167,239 (79.9%) adults with blunt and 20,643 (82.3%) adults with penetrating injury mechanisms. AUC and BIC estimates for the re-classified TRISS models were superior to the conventionally defined TRISS models. While having better predictive precision, the complexity associated with the best 10-category model resulted in the best 5-category model being preferred for penetrating mechanism injuries and being negligibly inferior for blunt mechanism injuries.

DISCUSSION

Substantial improvements in the predictive power of TRISS were demonstrated by reclassifying the component variables and treating the variable categories nominally. However, before anew TRISS model with updated coefficients can be published, variable interactions and the effect of missing data needs thorough statistical evaluation.

A review of injury epidemiology in the UK and Europe: some methodological considerations in constructing rates

BACKGROUND

Serious injuries have been stated as a public health priority in the UK. However, there appears to be a lack of information on population-based rates of serious injury (as defined by a recognised taxonomy of injury severity) at national level from either official statistics or research papers. We aim to address this through a search and review of literature primarily focused within the UK and Europe.

METHODS

The review summarizes research papers on the subject of population based injury epidemiology published from 1970 to 2008. We examined critically methodological approaches in measuring injury incident rates including data sources, description of the injury pyramid, matching numerator and denominator populations as well as the relationship between injury and socioeconomic status.

RESULTS

National representative rates come from research papers using official statistics sources, often focusing on mortality data alone. Few studies present data from the perspective of an injury pyramid or using a standardized measure of injury severity, i.e. Injury Severity Score (ISS). The population movement that may result in a possible numerator - denominator mismatch has been acknowledged in five research studies and in official statistics. The epidemiological profile shows over the past decades in UK and Europe a decrease in injury death rates. No major trauma population based rates are available within well defined populations across UK over recent time periods. Both fatal and non-fatal injury rates occurred more frequently in males than females with higher rates in males up to 65 years, then in females over 65 years. Road traffic crashes and falls are predominant injury mechanisms. Whereas a straightforward inverse association between injury death rates and socio-economic status has been observed, the evidence of socioeconomic inequalities in non-fatal injuries rates has not been wholly consistent.

CONCLUSION

New methodological approaches should be developed to deal with the study design inconsistencies and the knowledge gaps identified across this review. Trauma registries contain injury data from hospitals within larger regions and code injury by Abbreviated Injury Scale enabling information on severity; these may be reliable data sources to improve understanding of injury epidemiology.

Despite the increasing use of nonoperative management of firearm trauma, shotgun injuries still require aggressive operative management

BACKGROUND

The energy dissipation between gunshot and shotgun blasts is very different. Injuries from shotgun blasts vary depending on the distance of the victim from the shooter, the choke of the shotgun, the pellet load, and the wad of the ammunition. We postulated that gunshot and shotgun blasts create different injury patterns that dictate different treatment plans.

METHODS

Medical records of patients with gunshot and shotgun trauma were reviewed from 1998 through 2007 at our university-based trauma center. Statistical comparisons were made via Fisher's test or t-test calculations.

RESULTS

We evaluated 2833 patients injured by firearms; of these 61 had shotgun wounds (2.2%). The remainder sustained gunshot wounds. Mortality between shotgun and gunshot trauma patients was similar (7% versus 9%, respectively, P=0.8). There was no difference in the mean Injury Severity Score (ISS) (13.7+/-1.6 versus 12.9+/-0.2; P=0.6). Overall, 61% of patients underwent operative intervention after shotgun injuries versus 36% of patients with gunshot wounds (P<0.0001). Patients surviving shotgun injuries had a longer length of stay (10.1+/-2.0 d versus 5.9+/-0.21, P<0.05).

CONCLUSIONS

Although the injury severity was similar, injuries from shotguns required more operations and resource utilization. Shotgun blasts can create impressive superficial injuries as well as significant deep organ damage. An aggressive operative approach to managing shotgun trauma is advantageous.

Severity of injury does not have any impact on posttraumatic stress symptoms in severely injured patients

BACKGROUND

Due to improved surgical techniques and more efficient decision making in treating severely injured patients, survival rates have increased over the years. This study was initiated to evaluate the incidence and identify risk factors for developing posttraumatic stress symptoms, using both extensive trauma-related data and data assessing the psychological trauma, in a population of severely injured patients.

PATIENTS AND METHODS

79 patients admitted to the Department of Multitrauma and Spinal Cord Injury at Sunnaas Rehabilitation Hospital from 2003 to 2005, prospectively completed semistructured psychological interviews and questionnaires, such as Impact of Event Scale-Revised. In addition, extensive injury-related data, such as injury severity score (ISS), new injury severity score (NISS), and probability of survival (PS) were collected.

RESULTS

39% had multiple trauma, 34% had multiple injuries including spinal cord injuries, and 27% had isolated spinal cord injuries. Mean NISS was 31.5 (S.D. 13.7). 6% met diagnostic criteria for posttraumatic stress disorder (PTSD) and 9% met the criteria for subsyndromal PTSD. Injury-related data did not influence the prevalence of posttraumatic stress symptoms, however, some psychosocial variables did have a significant impact.

CONCLUSIONS

We found a low incidence of PTSD and subsyndromal PTSD. No significant differences were found between the patients suffering from posttraumatic stress symptoms and the non-symptoms group in relation to injury-related data such as ISS/NISS, PS, or multiple trauma versus spinal cord injury. The most evident risk factors for developing posttraumatic stress symptoms were symptoms of anxiety, female gender and negative attitudes toward emotional expression.

Comparison of the new injury severity score and the injury severity score in multiple trauma patients

OBJECTIVE

To assess whether these characteristics of less misclassification and greater area under receiver operator characteristic (ROC) curve of the new injury severity score (NISS) are better than the injury severity score (ISS) as applying it to our multiple trauma patients registered into the emergency intensive care unit (EICU).

METHODS

This was a retrospective review of registry data from 2 286 multiple trauma patients consecutively registered into the EICU from January 1,1997 to December 31, 2006 in the Second Affiliated Hospital, Medical School of Zhejiang University in China. Comparisons between ISS and NISS were made using misclassification rates, ROC curve analysis, and the H-L statistics by univariate and multivariate logistic progression model.

RESULTS

Among the 2 286 patients, 176 (7.7%) were excluded because of deaths on arrival or patients less than 16 years of age. The study population therefore comprised 2 110 patients. Mean EICU length of stay (LOS) was 7.8 days ?2.4 days. Compared with the blunt injury group, the penetrating injury group had a higher percentage of male, lower mean EICU LOS and age. The most frequently injured body regions were extremities and head/neck, followed by thorax, face and abdomen in the blunt injury group; whereas, thorax and abdomen were more frequently seen in the penetrating injury group. The minimum misclassification rate for NISS was slightly less than ISS in all groups (4.01% versus 4.49%). However, NISS had more tendency to misclassify in the penetrating injury group. This, we noted, was attributed mainly to a higher false-positive rate (21.04% versus 15.55% for ISS, t equal to 3.310, P less than 0.001), resulting in an overall misclassification rate of 23.57% for NISS versus 18.79% for ISS (t equal to 3.290, P less than 0.001). In the whole sample, NISS presented equivalent discrimination (area under ROC curve: NISS equal to 0.938 versus ISS equal to 0.943). The H-L statistics showed poorer calibration (48.64 versus 32.11, t equal to 3.305, P less than 0.001) in the penetrating injury group.

CONCLUSIONS

NISS should not replace ISS because they share similar accuracy and calibration in predicting multiple blunt trauma patients. NISS may be more sensitive but less specific than ISS in predicting mortality in certain penetrating injury patients.

Ten years of new injury severity score (NISS): is it a possible change?

The article is a bibliographic review which intends to present the actual range of researches comparing the Injury Severity Score (ISS) and the New Injury Severity Score (NISS). Databases were searched using the keyword NISS, with 42 articles, 23 of which didn't compare the two indexes. Most part of the 19 selected articles showed that NISS has been more accurate in predicting the outcomes (dependent variables) than ISS, moreover in severe and specific trauma. Studies with populations between 1,000 and 10,000 resulted in NISS-favorable results, whereas studies with populations larger than 10,000 or smaller than 1,000 showed either NISS-favorable results or no difference between the two groups. However, there were no studies showing ISS-favorable results. These results and the easier calculation of NISS lead to a future replacement of ISS by NISS.

The Utstein template for uniform reporting of data following major trauma: a joint revision by SCANTEM, TARN, DGU-TR and RITG

BACKGROUND

In 1999, an Utstein Template for Uniform Reporting of Data following Major Trauma was published. Few papers have since been published based on that template, reflecting a lack of international consensus on its feasibility and use. The aim of the present revision was to further develop the Utstein Template, particularly with a major reduction in the number of core data variables and the addition of more precise definitions of data variables. In addition, we wanted to define a set of inclusion and exclusion criteria that will facilitate uniform comparison of trauma cases.

METHODS

Over a ten-month period, selected experts from major European trauma registries and organisations carried out an Utstein consensus process based on a modified nominal group technique.

RESULTS

The expert panel concluded that a New Injury Severity Score > 15 should be used as a single inclusion criterion, and five exclusion criteria were also selected. Thirty-five precisely defined core data variables were agreed upon, with further division into core data for Predictive models, System Characteristic Descriptors and for Process Mapping.

CONCLUSION

Through a structured consensus process, the Utstein Template for Uniform Reporting of Data following Major Trauma has been revised. This revision will enhance national and international comparisons of trauma systems, and will form the basis for improved prediction models in trauma care.

The injury severity score or the new injury severity score for predicting mortality, intensive care unit admission and length of hospital stay: experience from a university hospital in a developing country

INTRODUCTION

Limited research has been performed to compare the predictive abilities of the injury severity score (ISS) and the new ISS (NISS) in the developing world.

PATIENTS AND METHODS

From January 2001 until January 2003 all trauma patients admitted to the American University of Beirut Medical Centre were enrolled. The statistical performance of the ISS/NISS in predicting mortality, admission to the intensive care unit (ICU) and length of hospital stay (LOS dichotomised as <10 or > or =10 days) was evaluated using receiver operating characteristic and the Hosmer-Lemeshow calibration statistic.

RESULTS

A total of 891 consecutive patients were enrolled. The ISS and NISS were equivalent in predicting survival, and both performed better in patients younger than 65 years of age. However, the ISS predicted ICU admission and LOS better than the NISS. However, these predictive abilities were lower for the geriatric trauma patients aged 65 years and above compared to the other age groups.

DISCUSSION

There are conflicting results in the literature about the abilities of ISS and NISS to predict mortality. However, this is the first study to report that ISS has a superior ability in predicting both LOS and ICU admission.

CONCLUSION

The scoring of trauma severity may need to be individualised to different countries and trauma systems.

Long-Term Multidimensional Functional Consequences of Severe Multiple Injuries Two Years After Trauma: A Prospective Longitudinal Cohort Study

BACKGROUND

The assessment of outcome after multiple injuries in a rehabilitation perspective is increasingly important in trauma research. The purpose of this study was to assess functioning and quality of life after severe injuries using a prospective cohort design.

METHODS

One hundred and five patients with a New Injury Severity Score >15, aged 18 to 67 years, and admitted to a Level I trauma center were included consecutively starting January 2002 through June 2003. Outcomes were assessed 6 weeks after discharge and 1 and 2 years after injury. Self-reported functioning and quality of life was measured by Short Form (SF)-36, World Health Organization Disability Assessment Schedule II (WHODAS II) and a cognitive function scale (COG).

RESULTS

Mean age was 35.3 years (standard deviation [SD], 14.0), 83% were male. Mean New Injury Severity Score was 34.6 (SD, 12.6). Disease burden measured by SF-36 showed scores below the general population. Effect sizes showed that the largest difference was for physical functioning, social functioning, and physical and emotional role functioning. The WHODAS II disability score showed substantially worse functioning compared with general population data. Profession, injury severity, pain, and physical, cognitive, and social functioning made independent contributions to WHODAS II 2 years after injury and explained 69% of the variance of the model.

CONCLUSIONS

Long-lasting functional problems after multiple injuries affect most life domains. Knowledge about the reduced physical, mental, cognitive, social, and role functioning should impact the rehabilitation services provided for severely injured patients, from primary care to community rehabilitation.

Road Crash Casualties: Characteristics of Police Injury Severity Misclassification

BACKGROUND

In most countries, epidemiologic knowledge of road crash injury is mainly based on police data, as they very often are the only available data at the nation-wide level. However their validity is of some concern. We focus here on the police severity classification of 'serious' and 'slight' casualties in France. We want to know how the police classification compares with a trauma severity scale, so that we could correctly interpret police based studies.

METHOD

The study is based on the Rhône county (population 1.6 million) during the 1997 to 2001 period. Police data have been linked with a road trauma registry, so that both police and New Injury Severity Score (NISS) classifications are available on 14,342 casualties. The police classification of 'slight' and 'serious' casualties is compared with the registry classification grouped into NISS 1-15 and NISS 16-75 categories. We conduct multivariate analyses of the probability of police severity misclassification, over and under-classification, as a function of crash and casualty characteristics.

RESULTS

Kappa is estimated at 0.41; the sensitivity of the police classification is 72% and the positive predictive value is 35%. Pedestrian and motorcyclist casualties are the most likely to be over-classified (Relative Risk [RR] = 1.4 and RR = 1.2, respectively compared with car occupants). The 'rural police' are more likely to over-classify than the other police forces (RR = 3.1). Over-classification decreased during the 1997 to 2001 period whereas under- classification increased.

CONCLUSION

These misclassification characteristics must be kept in mind when interpreting severity results based on police data. We are working on obtaining unbiased nation-wide estimates of severity figures.

Return to Work After Severe Multiple Injuries: A Multidimensional Approach on Status 1 and 2 Years Postinjury

BACKGROUND

The assessment of factors associated with return to work (RTW) after multiple trauma is important in trauma research. Goals in rehabilitation should comprise RTW. The purpose of this study was to examine the RTW rate and which factors predicted RTW for patients with severe multiple injuries using a prospective cohort design.

METHODS

In all, 100 patients with a New Injury Severity Score (NISS) >15, aged 18 to 67 years and admitted to a trauma referral center, were included starting January 2002 through June 2003. Outcomes were assessed 6 weeks after discharge and 1 and 2 years postinjury. Instruments were the Brief Approach/Avoidance Coping Questionnaire, Multidimensional Health Locus of Control, Short Form-36, the World Health Organization Disability Assessment Schedule II, and a cognitive function scale (COG).

RESULTS

Mean age was 34.5 years (SD 13.5), 83% were male, and 66% were blue-collar workers. Mean NISS was 35.1 (SD 12.7). At 1 year, 28% achieved complete RTW, 43% at 2 years. Mean time back to work was 12.8 months (SD 5.9). Differences between the RTW and not complete RTW (NRTW) groups concerned personal and demographic variables, and physical and psychosocial functioning. Survival analysis showed that risk factors for NRTW were lower education, length of stay in hospital/rehabilitation >20 weeks, and low social functioning shortly after the return home.

CONCLUSION

The majority of the patients had not completely returned to work 2 years postinjury. Demographic and injury related factors and social functioning were significant predictors of RTW status.

Scoring of anatomic injury after trauma: AIS 98 versus AIS 90--do the changes affect overall severity assessment?

BACKGROUND

Although several changes were implemented in the 1998 update of the abbreviated injury scale (AIS 98) versus the previous AIS 90, both are still used worldwide for coding of anatomic injury in trauma. This could possibly invalidate comparisons between systems using different AIS versions. Our aim was to evaluate whether the use of different coding dictionaries affected estimation of Injury Severity Score (ISS), New Injury Severity Score (NISS) and probability of survival (Ps) according to TRISS in a hospital-based trauma registry.

MATERIALS AND METHODS

In a prospective study including 1654 patients from Ulleval University Hospital, a Norwegian trauma referral centre, patients were coded according to both AIS 98 and AIS 90. Agreement between the classifications of ISS, NISS and Ps according to TRISS methodology was estimated using intraclass correlation coefficients (ICC) with 95% CI.

RESULTS

ISS changed for 378 of 1654 patients analysed (22.9%). One hundred and forty seven (8.9%) were coded differently due to different injury descriptions and 369 patients (22.3%) had a change in ISS value in one or more regions due to the different scoring algorithm for skin injuries introduced in AIS 98. This gave a minimal change in mean ISS (14.74 versus 14.54). An ICC value of 0.997 (95% CI 0.9968-0.9974) for ISS indicates excellent agreement between the scoring systems. There were no significant changes in NISS and Ps.

CONCLUSIONS

There was excellent agreement for the overall population between ISS, NISS and Ps values obtained using AIS 90 and AIS 98 for injury coding. Injury descriptions for hypothermia were re-introduced in the recently published AIS 2005. We support this change as coding differences due to hypothermia were encountered in 4.3% of patients in the present study.