Validation of the Norwegian survival prediction model in trauma (NORMIT) in Swedish trauma populations.

The Injury Severity Score (ISS) has served as the standard summary measure of anatomic injury for more than 20 years. Nevertheless, the ISS has an idiosyncrasy that both impairs its predictive power and complicates its calculation. We present here a simple modification of the ISS called the New Injury Severity Score (NISS), which significantly outperforms the venerable but dated ISS as a predictor of mortality. Retrospective calculation of NISS and comparison of NISS with prospectively calculated ISS. The NISS is defined as the sum of the squares of the Abbreviated Injury Scale scores of each of a patient's three most severe Abbreviated Injury Scale injuries regardless of the body region in which they occur. NISS values were calculated for every patient in two large independent data sets: 3,136 patients treated during a 4-year period at the American College of Surgeons' Level I trauma center in Albuquerque, New Mexico, and 3,449 patients treated during a 4-year period at the American College of Surgeons' Level I trauma center at the Emanuel Hospital in Portland, Oregon. The power of NISS to predict mortality was then compared with previously calculated ISS values for the same patients in each of the two data sets. We find that NISS is not only simple to calculate but more predictive of survival as well (Albuquerque: receiver operating characteristic (ROC) ISS = 0.869, ROC NISS = 0.896, p < 0.001; Portland: ROC ISS = 0.896, ROC NISS = 0.907,p < 0.004). Moreover, NISS provides a better fit throughout its entire range of prediction (Hosmer Lemeshow statistic for Albuquerque ISS = 29.12, NISS = 8.88; Hosmer Lemeshow statistic for Portland ISS = 83.48, NISS = 19.86). NISS should replace ISS as the standard summary measure of human trauma.

BackgroundAnatomy-based injury severity scores are commonly used with physiological scores for reporting severity of injury in a standardized manner. However, there is lack of consensus on choice of scoring system, with the commonly used injury severity score (ISS) performing poorly for certain sub-groups, eg head-injured patients. We hypothesized that adding a dichotomous variable for polytrauma (yes/no for Abbreviated Injury Scale (AIS) scores of 3 or more in at least two body regions) to the New Injury Severity Score (NISS) would improve the prediction of in-hospital mortality in injured patients, including head-injured patients—a subgroup that has a disproportionately high mortality. Our secondary hypothesis was that the ISS over-estimates the risk of death in polytrauma patients, while the NISS under-estimates it.MethodsUnivariate and multivariable analysis was performed on retrospective cohort data of blunt injured patients aged 18 and over with an ISS over 9 from the Singapore National Trauma Registry from 2011–2013. Model diagnostics were tested using discrimination (c-statistic) and calibration (Hosmer-Lemeshow goodness-of-fit statistic). All models included age, gender, and comorbidities.ResultsOur results showed that the polytrauma and NISS model outperformed the other models (polytrauma and ISS, NISS alone or ISS alone) in predicting 30-day and in-hospital mortality. The NISS underestimated the risk of death for patients with polytrauma, while the ISS overestimated the risk of death for these patients.When used together with the NISS and polytrauma, categorical variables for deranged physiology (systolic blood pressure of 90 mmHg or less, GCS of 8 or less) outperformed the traditional ‘ISS and RTS (Revised Trauma Score)’ model, with a c-statistic of greater than 0.90. This could be useful in cases when the RTS cannot be scored due to missing respiratory rate.DiscussionThe NISS and polytrauma model is superior to current scores for prediction of 30-day and in-hospital mortality. We propose that this score replace the ISS or NISS in institutions using AIS-based scores.ConclusionsAdding polytrauma to the NISS or ISS improves prediction of 30-day mortality. The superiority of the NISS or ISS depends on the proportion of polytrauma and head-injured patients in the study population.

ObjectiveTo 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.SettingThis study was based at a level I trauma center in Taiwan.MethodsData 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.ResultsAccording 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.ConclusionsEISS 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.

BackgroundThe objective of this study is to propose three new adjustments to the Trauma and Injury Severity Score (TRISS) equation and compare their performances with the original TRISS as well as this index with coefficients adjusted for the study population.MethodsThis multicenter, retrospective study evaluated trauma victims admitted to two hospitals in São Paulo-Brazil and San Diego-EUA between January 1st, 2006, and December 31st, 2010. The proposed models included a New Trauma and Injury Severity Score (NTRISS)-like model that included Best Motor Response (BMR), systolic blood pressure (SBP), New Injury Severity Score (NISS), and age variables; a TRISS peripheral oxygen saturation (SpO2) model that included Glasgow Coma Scale (GCS), SBP, SpO2, Injury Severity Score, and age variables; and a NTRISS-like SpO2 model that included BMR, SBP, SpO2, NISS, and age variables. All equations were adjusted for blunt and penetrating trauma coefficients. The model coefficients were established by logistic regression analysis. Receiver operating characteristic (ROC) curve analysis was used to evaluate the performance of the models.ResultsThe original TRISS (area under the curve (AUC) = 0.90), TRISS with adjusted coefficients (AUC = 0.89), and the new proposals (NTRISS-like, TRISS SpO2, and NTRISS-like SpO2) showed no difference in performance (AUC = 0.89, 0.89, and 0.90, respectively).ConclusionsThe new models demonstrated good accuracy and similar performance to the original TRISS and TRISS adjusted for coefficients in the study population; therefore, the new proposals may be useful for the assessments of quality of care in trauma patients using variables that are routinely measured and recorded.

Aim: Falls from a height and their subsequent injuries and traumas can cause morbidity and death. In the present study, ISS, NISS, RTS, and TRISS values were analyzed to assess mortality probabilities of patients who fell from a height. Materials and Methods: Patients' age, gender, height of falls (0-2 m, 3-5 m, and 6 m and above), organ pathologies, and ISS, NISS, RTS, and TRISS scores were evaluated in terms of mortality. Results: Regarding the survival rate, no statistically significant difference was found between age and gender (P > 0.05). We determined that all trauma scores were correlated with mortality, and that as Injury Severity Score (ISS), New Injury Severity Score (NISS), and Trauma and Injury Severity Score (TRISS) values increased, and as Revised Trauma Score (RTS) values decreased, the mortality rate tended to increase. The area under the curve in the Receiver Operating Characteristic (ROC) analysis was 0.991 for TRISS, 0.910 for ISS, and 0.915 for NISS (P > 0.001). The most satisfactory cut-off point for TRISS was 73.5 and at that point, we found the best sensitivity, specificity, and positive and negative predictive values. Conclusions: In conclusion, the data showed that TRISS values can be used with high reliability when this value is over 73.5 and any score above it has high specificity and mortality.

Older adults are more vulnerable to trauma because of reduced physiological reserve, a higher burden of comorbidities, and increased frailty. However, traditional trauma scoring systems may not fully reflect these age-related factors. This study aimed to evaluate the predictive performance of classical trauma scoring systems and to examine the association of frailty and selected laboratory markers with 30-day mortality among older adults with traffic-related injuries. This retrospective study included patients aged ≥65 years who presented to a tertiary emergency department with traffic-related injuries between 2021 and 2024. Demographic, clinical, and laboratory data were recorded, along with frailty status assessed using the Clinical Frailty Scale (CFS). Trauma severity was evaluated using the Injury Severity Score (ISS), New Injury Severity Score (NISS), Trauma and Injury Severity Score (TRISS), Revised Trauma Score (RTS), Glasgow Age Pressure (GAP), Mechanism Glasgow Age Pressure (MGAP), and the Geriatric Trauma Outcome Score (GTOS). The primary outcome was 30-day mortality. Receiver operating characteristic (ROC) analysis and univariate logistic regression were performed to identify predictors of mortality. Among 325 patients (mean age: 73.4 years; 64.9% male), 30-day mortality was 4.9%. Chronic kidney disease was the only comorbidity significantly associated with mortality (OR: 7.69; P = .005). Mortality was associated with higher INR, lactate, and creatinine levels; lower platelet counts, Glasgow Coma Scale (GCS) scores, and systolic blood pressure; and increased respiratory rate. ISS, TRISS, and NISS demonstrated the highest discriminatory power (AUC > 0.99). Among laboratory parameters, lactate showed the strongest predictive performance (AUC = 0.910). In multivariate analysis, increased respiratory rate and higher NISS remained the only independent predictors of 30-day mortality. In this cohort of older adults with traffic-related trauma, increased respiratory rate and higher NISS were the main independent predictors of 30-day mortality. Frailty assessed by the Clinical Frailty Scale was not independently associated with short-term mortality. These findings suggest that, in high-energy traffic-related trauma, injury severity and acute physiological response may be more decisive for short-term outcomes than frailty status alone.

IntroductionGeriatric patients have a high risk of poor outcomes after trauma and is a rapid-increasing group within the trauma population. Given the need to ensure that the trauma system is targeted, efficient, accessible, safe and responsive to all age groups the aim of the present study was to explore the epidemiology and characteristics of the Norwegian geriatric trauma population and assess differences between age groups within a national trauma system. Materials and methodsThis retrospective analysis is based on data from the Norwegian Trauma Registry (2015-2018). Injury severity was scaled using the Abbreviated Injury Scale (AIS), and the New Injury Severity Score (NISS). Trauma patients 16 years or older with NISS ≥9 were included, dichotomized into age groups 16–64 years (Group 1, G1) and ≥65 years (Group 2, G2). The groups were compared with respect to differences in demographics, injury characteristics, management and outcome. Descriptive statistics and relevant parametric and non-parametric tests were used. ResultsGeriatric patients proved to be at risk of sustaining severe injuries. Low-energy falls predominated in G2, and the AIS body regions ‘Head’ and ‘Pelvis and lower extremities’ were most frequently injured. Crude 30-day mortality was higher in G2 compared to G1 (G1: 2.9 vs. G2: 13.6%, P<0.01) and the trauma team activation (TTA) rate was lower (G1: 90 vs. G2: 73%, P<0.01). A lower proportion of geriatric patients were treated by a physician prehospitally (G1: 30 vs. G2: 18%, [NISS 15–24], P<0.01) and transported by air-ambulance (G1: 24 vs. G2: 14%, [NISS 15–24], P<0.01). Median time from alarm to hospital admission was longer for geriatric patients (G1: 71 vs. G2: 78 min [NISS 15–24], P<0.01), except for the most severely injured patients (NISS≥25). ConclusionIn this nationwide study comparing adult and geriatric trauma patients, geriatric patients were found to have a higher mortality, receive less frequently advanced prehospital treatment and transportation, and a lower TTA rate. This is surprising in the setting of a Nordic country with free access to publicly funded emergency services, a nationally implemented trauma system with requirements to pre- and in-hospital services and a national trauma registry with high individual level coverage from all trauma-receiving hospitals. Further exploration and a deeper understanding of these differences is warranted.

The Injury Severity Score (ISS) has been observed consistently to be a robust predictor of postinjury multiple organ failure (MOF). However, the ISS fails to account for multiple injuries to the same body region. Recently, the "new" ISS (NISS) has been proposed to address this shortcoming. Preliminary studies suggest the NISS is superior to the ISS in predicting trauma mortality. Our purpose was to determine whether the NISS is a better predictor of postinjury MOF than the ISS. A total of 558 patients admitted to our Level I trauma center with ISS > 15, age > 15 years, and survival > 48 hours were prospectively identified; 101 (18%) developed postinjury MOF. Data characterizing postinjury MOF were collected, and the NISS was calculated retrospectively. The ISS and NISS were compared as univariate predictors of MOF. Multivariate analysis was used to determine whether substitution of NISS for ISS resulted in a superior predictive model. In 295 patients (53%), the NISS was greater than the ISS. This subgroup of patients experienced a greater frequency of MOF (26.7% vs. 8.3%, p < 0.0001), a higher mortality (12.8% vs. 4.9%, p < 0.001), and a higher early transfusion requirement (6.7 U vs. 3.6 U, p < 0.0001) compared with the group in which NISS equaled ISS. Moreover, the NISS yielded better separation between patients with and without MOF reflected by the greater difference in median NISS scores compared with ISS scores. The multivariate predictive model, including NISS, showed a better goodness of fit compared with the same model that included ISS. The NISS is superior to the ISS in the prediction of postinjury MOF. This measure of tissue injury severity should replace the ISS in trauma research.

The Injury Severity Score or the New Injury Severity Score for predicting intensive care unit admission and hospital length of stay?

IntroductionAnatomic 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.MethodsEligible 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.ResultsThe 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.ConclusionsThe 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.

The New Injury Severity Score (NISS) was introduced in 1997 to improve outcome prediction based on anatomical severity scoring in trauma victims. Studies on populations of blunt trauma victims indicate that the NISS, predicts better than the Injury Severity Score (ISS) mortality post-injury, which is why the NISS has been recommended as the new "gold standard" for severity scoring. However, so far the accuracy of the NISS for penetrating injuries has not been validated against the ISS. ISS and NISS scores were collected retrospectively for 1,787 war- and landmine victims in North Iraq. All victims only had penetrating injuries. The two tests were compared for prediction of short-term mortality and post-operative complications using Receiver Operating Characteristics (ROC) analysis. Both the ISS and the NISS predicted mortality with high accuracy (ROC area under curve 0.9). There were no significant differences between the two tests. The predictive accuracy for post-operative complications was moderate for both tests (ROC-AUC < 0.8), with the NISS performing significantly better than the ISS. The NISS does not perform better than the ISS in penetrating injuries. However, this study was done on a low-risk trauma population, thus the results should not be extrapolated to high severity trauma. Due to statistical shortcomings in studies previously published, studies on far larger cohorts are necessary before the NISS should be adopted as the new "gold standard" for severity scoring.

To explore the value of the injury severity score (ISS) and the new injury severity score (NISS) for evaluating injuries and predicting complications (pneumonia and respiratory failure) and poor prognoses (in-hospital tracheal intubation, extended length of hospital stay, ICU admission, prolonged ICU stay, and death) in patients with thoracic trauma. The data of consecutive patients with thoracic trauma who were admitted to the department of cardiothoracic surgery of a tertiary hospital between January 2018 and December 2021 were retrospectively collected. ISS and NISS were calculated for each patient. The study outcomes were complications and poor prognoses. The differences in ISS and NISS between patients with complications and poor prognoses and patients without the abovementioned conditions were compared using the Mann‒Whitney U test. Discrimination and calibration of ISS and NISS in predicting outcomes were compared using the area under the receiver operating characteristic (ROC) curve (AUC) and Hosmer‒Lemeshow (H-L) statistic. A total of 310 patients were included. ISS and NISS of patients with complications and poor prognoses were greater than those of patients without complications and poor prognoses, respectively. The discrimination of ISS in predicting pneumonia, respiratory failure, in-hospital tracheal intubation, extended length of hospital stay, ICU admission, prolonged ICU stay, and death (AUCs: 0.609, 0.721, 0.848, 0.784, 0.763, 0.716, and 0.804, respectively) was not statistically significantly different from that of NISS in predicting the corresponding outcomes (AUCs: 0.628, 0.712, 0.795, 0.767, 0.750, 0.750, and 0.818, respectively). ISS showed better calibration than NISS for predicting pneumonia, respiratory failure, in-hospital tracheal intubation, extended length of hospital stay, and ICU admission but worse calibration for predicting prolonged ICU stay and death. ISS and NISS are both suitable for injury evaluation. There was no statistically significant difference in discrimination between ISS and NISS, but they had different calibrations when predicting different outcomes.

The Injury Severity Score (ISS) has been validated in numerous studies and has become one of the most common trauma scoring systems since its inception. The ISS equation was later modified to create the New Injury Severity Score (NISS). By using the three most severe injuries regardless of body region, the NISS seems well suited to describe patients of penetrating trauma, where injuries often cluster within a single body region. We hypothesized that NISS would better predict outcomes than ISS in penetrating trauma patients. An analysis (June 2008 to March 2009) of all severely injured (length of hospital stay ≥ 48 hours, intensive care unit admission, interhospital transfer, or death) penetrating trauma patients revealed final study sample of 256 patients. ISS and NISS were compared as predictors for both mortality and complications through area under the receiver operating characteristic curve, Hanley-McNeil test, multiple-variable logistic regression, and Hosmer-Lemeshow goodness-of-fit test analysis. Of 256 study patients, 195 (76.2%) survived until discharge. The mean (ISS, 21.7 ± 21.1 vs. NISS, 27.4 ± 22.0; p < 0.001) and median (ISS, 14.0 vs. NISS, 21.0) ISS was lower than those of the NISS. Overall, 173 patients (67.6%) had discordant scores with 26% and 43% having scores greater than 25 (ISS and NISS, respectively, p < 0.01). The mortality area under the curve (AUC) for NISS was greater than the AUC for ISS in all penetrating patients (0.930 vs. 0.885, p = 0.008), those with penetrating torso injuries (NISS, 0.934 vs. ISS, 0.881, p < 0.001), and those with severe (score > 25) injuries (NISS, 0.845 vs. ISS, 0.761, p < 0.001). In patients surviving for more than 48 hours, the complications AUC for NISS was also greater than the AUC for ISS (NISS, 0.838 vs. ISS, 0.784; p = 0.023). The NISS outperformed ISS as a predictor of both mortality and complications in civilian penetrating trauma patients. These results indicate that NISS is a superior scoring system for patients with penetrating injuries. Prognostic study, level III.

TRAUMA CARE: HIGHLY DEMANDING, TREMENDOUS BENEFITS

&lt;p dir="ltr"&gt;Early and accurate prioritization of trauma patients, known as triage, is crucial to identify those in need of emergency life-saving interventions. Excellent trauma care relies strongly on correct triage, which impacts patients' experiences and outcomes. Undertriage has been shown to be associated with an elevated risk of undetected injuries and missed interventions. However, the definition of severe trauma is still debatable. This thesis aimed to study aspects and consequences of in-hospital triage, examine over-and undertriage, trauma care processes, experiences and outcomes, providing insights to improve care for this patient group. Qualitative and quantitative approaches were used. Paper I was a 'before and after' study where the effect of a criteria-directed protocol for in-hospital triage of trauma patients in a Swedish trauma center was evaluated. The results showed that by using the protocol, overtriage was reduced from 74% to 58% while undertriage increased from 7% to 10%. No preventable deaths were detected after peer-review of those undertriaged. In Paper II, trauma patients' experiences after initial trauma management were explored, using individual face-to-face semi-structured interviews. The interviews were recorded, transcribed and analyzed using qualitative content analysis. Patients reported emotional responses to the trauma, physical discomfort and feeling prioritized or being ignored by the trauma team. The main category that emerged was: "Feeling safe in a frightening situation". In Paper III, the two scoring systems, the anatomic New Injury Severity score (NISS) and the physiology-based GAP score, for prediction on ICU-admission and 30-day mortality after trauma, were evaluated: in the Swedish trauma population. The findings showed that the GAP- score was better at predicting 30-day mortality compared to NISS, with AUROC (95% CI) values of 0.92 (0.91-0.93) and 0.84 (0.83-0.85) respectively, while NISS performed better than GAP at predicting ICU-admission. Both scoring systems were less accurate in predicting mortality in the older patient group. In Paper IV, undertriaged trauma patients were characterized and compared to non- undertriaged trauma patients, in age groups, to investigate potential differences in trauma care processes and 30-day mortality. The study results showed that undertriaged patients had fewer intubations, longer time to CT-scan and fewer admissions to ICU, were less severely injured, and had lower mortality compared to non- undertriaged patients. This demonstrates that undertriage was not associated with poorer outcomes compared to non-undertriage, in the current study.&lt;/p&gt;&lt;h3&gt;List of scientific papers&lt;/h3&gt;&lt;p dir="ltr"&gt;I. A criteria-directed protocol for in-hospital triage of trauma patients&lt;b&gt;. &lt;/b&gt;&lt;b&gt;Granström A,&lt;/b&gt; Strömmer L, Schandl A, Östlund A. European Journal of Emergency Medicine 2018;25(1):25-31 (Included in Licentiate thesis). &lt;a href="https://doi.org/10.1097/mej.0000000000000397" rel="noreferrer" target="_blank"&gt;https://doi.org/10.1097/mej.0000000000000397&lt;/a&gt;&lt;/p&gt;&lt;p dir="ltr"&gt;II. Patient experiences of initial trauma care&lt;b&gt;. &lt;/b&gt;&lt;b&gt;Granström A,&lt;/b&gt; Strömmer L, Falk AC, Schandl A. International Emergency Nursing 2019;42:25-29 (Included in Licentiate thesis). &lt;a href="https://doi.org/10.1016/j.ienj.2018.08.003" rel="noreferrer" target="_blank"&gt;https://doi.org/10.1016/j.ienj.2018.08.003&lt;/a&gt;&lt;/p&gt;&lt;p dir="ltr"&gt;III. Using the GAP score as a compliment to the NISS score in identifying severely injured patients- A registry-based cohort study of adult trauma patients in Sweden&lt;b&gt;. &lt;/b&gt;&lt;b&gt;Granström A,&lt;/b&gt; Schandl A, Mårtensson J, Strömmer L. Injury 2024;55(9):111709. &lt;a href="https://doi.org/10.1016/j.injury.2024.111709" rel="noreferrer" target="_blank"&gt;https://doi.org/10.1016/j.injury.2024.111709&lt;/a&gt;&lt;/p&gt;&lt;p dir="ltr"&gt;IV. Impact of Undertriage on Trauma Care Processes and Mortality Across Age Groups&lt;b&gt;. &lt;/b&gt;&lt;b&gt;Granström A,&lt;/b&gt; Schandl A, Mårtensson J, Strömmer L. [Manuscript]&lt;/p&gt;