To evaluate the predictive value of the Maximum Injury Severity Score at a Level One Trauma Unit in South Africa compared to current objective systems. To evaluate the predictive value of the ISS versus the NISS in polytrauma trauma patients admitted to a level 1 trauma unit in South Africa. To assess the predictive value of a MISS in patients admitted to a Level 1 Trauma Unit in South Africa, compared with ISS and NISS.
A maximum injury severity score has better predictive value than the ISS or NISS for polytrauma patients admitted to a level 1 trauma unit in South Africa. The second part of this discussion will be the examination of three population groups, separated by age, in order to identify the difference in the spectrum of trauma, outcomes and a comparison of the predictive values of injury outcomes as already defined. In the last chapter, conclusions will be drawn based on the results of the analyzed data.
Conclusion
SECTION TWO: LITERATURE REVIEW
Introduction
Global burden of disease
South African context
To date, there have been numerous initiatives to combat the escalation of trauma-related deaths, but with little success. The current study was conducted at the Level I Trauma Unit of the Inkosi Albert Luthuli Central Hospital in Durban, KwaZulu/Natal, which opened in 2007.
Trauma scoring
The AIS is an anatomically based consensus-derived global severity scoring system (15) that classifies each injury in each body region according to its relative importance on a six-point ordinal scale. This represents the 'threat to life' associated with an injury and is not intended to represent a comprehensive measure of severity (16). Using the AIS score, an ISS value is calculated by summing the squares of the highest AIS scores in each of the three most severely injured ISS body regions.
ISS has a highly positively skewed distribution and its relationship with mortality and other outcomes is not linear. The score is retrospective and should only be calculated after all injuries have been identified. In contrast, the NISS is calculated by adding the squares of the three most severe AIS injuries, regardless of the body region of the ISS.
Current studies comparing ISS and NISS
The polytrauma patient is not always an adult with minimal co-morbidities such as physiological changes associated with both ends of the age spectrum, namely pediatric or geriatric patients. Undoubtedly, pediatric patients have different patterns of injury from causes that differ from those of adults due to their unique anatomical, physiological, and behavioral characteristics (30). As such, it is not surprising that when Grisoni et al (31) evaluated the ISS versus the NISS in a cohort of 9151 pediatric trauma patients, they found that the differences in the predictive abilities of the two scoring systems were insignificant.
In this subset of patients, due to reduced physiologic reserve, frailty, and pre-injury comorbidities, these patients have higher pre-injury morbidity and mortality than their younger counterparts ( 32 ). They also found that geriatric patients showed a physical injury pattern that differed from that of younger adult patients and had a higher severe injury score, worse outcome, and higher mortality than that of their younger counterparts.
Why MISS?
Other Trauma Scoring systems
Furthermore, the system is designed for use only after 24 hours of ICU admission and is therefore not applicable to the non-critically injured patient. In 2000, Kobusingye et al (36) looked at 736 patients in Uganda and designed a composite score that was easy to calculate and applicable to their resource-limited setting. Scoring of trauma is a basic requirement for trauma epidemiology and a robust cornerstone in predicting mortality and morbidity of trauma patients (26).
SECTION THREE: STUDY DESIGN AND RESEARCH METHODOLOGY
Study location
Study period
Research Aim
Ethics
Sampling
Data Collection
Data Analysis
A perfect test indicates detection of all true positives and no false positives and has a sensitivity of 1 and a 1-specificity of 0. Graphically, this is represented by a dot in the upper left corner of the graph and a area under the curve ( AUC) equal to 1. So the higher the AUC of an ROC curve produced by a test, the more effective the test.
Under these conditions, two ROC curve areas that have a statistically significant difference may have overlapping confidence intervals (19). A high (p > 0.05) p-value implies that the model is robust and there is no reason to believe that a model is not well calibrated (42). The H-L statistic was obtained from logistic regression models where the dependent variable was mortality and the independent variables were.
Outcomes
Limitations of the Study
SECTION FOUR: RESULTS AND DATA ANALYSIS
Characteristics of Study Cohort
Analysis of Injury Severity Scores
Analysis of injury mechanism (MOI)
Analysis of Gender: Males versus Females
The low H-L Ӽ2 statistic of 7.881 (p) suggested that the model was equally fit compared to the male group. The ROC curves were comparable if not better than the AUC values for the ISS, NISS and MISS.
Analysis of Length of Stay
Analysis of Number of Regions Injured (#RI)
DISTRIBUTION OF REGIONS INJURED
Group A (Paediatric, AGE ≤ 18 years) Data Analysis
Group B (Adult, 19 years ≥ AGE ≤ 54 years) Data Analysis
However, in the female group, ISS was the better predictor of mortality with a fractional increase. When LOS was compared with ISS, NISS and MISS, NISS was the better predictor of outcome.
Group C (Geriatric, AGE ≥ 55 years) Data Analysis
In this small group, transport-related injuries were the most common mechanism in 51 (79.7%) and MVC-pedestrians in 24 (37.5%). Findings in the female group were relatively similar, but the ISS (AUC 0.675, SD 17.037) had better calculated values compared to the NISS and MISS. LOS, ISS, NISS and MISS were poor predictors of mortality in this group.
In Chapter 5 I would like to conclude the findings from this study and hopefully also make recommendations.
SECTION FIVE: CONCLUSION
The resource-limited milieu in which we work, together with a high disease burden related to transport-related and interpersonal violence injuries and the paucity of local data, is what initiated this study. Was intended improvement based on the analysis of a reliable database that provides sufficient evidence of the task at hand. In this cohort based on the collected data and regardless of age, the NISS was superior to the ISS in predicting outcome.
The consistent benefit of the NISS demonstrated in this study underlines this concept of adding the three worst injuries regardless of location. To explain it further, the lesions with a lower AIS score, no matter how much, may not contribute to the patient's overall outcome, but rather contribute to the potential morbidity for which the patient may be at risk. In patients with multiple trauma there may be a limit to the physiological reserve.
In patients with minor injuries, anatomical assessments alone may be sufficient, while in those with critical injuries, a combined anatomical and physiological assessment seems more relevant. Length of stay was generally longer and did not affect patient outcome. Once the patient is ready to be transferred back to the referring hospital, the repatriation process can take up to two weeks, depending on how far the patient has to travel.
Second, our patients are ideally expected to be transferred back to at least one high-definition unit at the referring hospital. With the large differences in the capacities of the referring hospitals within our catchment area, this is not always possible. As such, while other injury severity scores such as the Kampala Trauma Score and the APACHE IV Score have gained some acceptance in recent publications, it is important to be.
Standardization of data collection and accurate record keeping can enable better understanding and contribute to improved service delivery in the future.
SECTION SIX: REFERENCES
Comparison of injury severity assessment and new injury severity assessment after penetrating trauma: a prospective analysis. The new injury severity score is a better predictor of mortality for patients with blunt injuries than the injury severity score. Injury Severity Score: A method for describing patients with multiple injuries and evaluating emergency care.
Injury Severity Score or New Injury Severity Score for predicting intensive care unit admission and length of hospital stay. Osler T, Baker S, Long W.A modification of the injury severity score that improves accuracy and simplifies assessment. Validation of the Injury Severity Score (ISS) in different populations: ISS better predicts mortality among Hispanics and females.
Comparison of the new injury score and injury severity in multiple trauma patients. The injury severity score or the new injury severity score for predicting mortality, intensive care unit admission and length of stay: Experience from a university hospital in a developing country. Balogh ZJ, Varga E, Tomka J, et al. The new injury grade is a better predictor of prolonged hospitalization and intensive care unit admission than the injury grade in patients with multiple orthopedic injuries.
Lavoie A, Moore L, LeSage N, et al. The New Injury Severity Score: A more accurate predictor of in-hospital mortality than injury severity. ICD-derived Injury Severity Score (ICISS) in a patient population treated in a designated Hong Kong trauma center. Osler TM, Baker SP, Long W.A Injury grade modification that both improves accuracy and simplifies scoring.
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.
SECTION SEVEN: APPENDICES
APPENDIX A. Protocol for Ethics Approval Title of study
Aim of study
Background and Literature
The subsequent modification of the ISS, the New Injury Severity Score (NISS), was proposed, not widely used. The Maximal Injury Severity Score (MISS) has not been studied and will be evaluated to improve its current predictive value when assessed in comparison to the ISS and NISS at a Level 1 Trauma Unit in Durban, South Africa.
Key References
Study design
Single centre, mainly severe trauma, retrospective data – so risk of bias from inaccurate notes, but unlikely due to consultant-led unit with regular audit and good clinical management. Ethical approval will be obtained from the Research and Ethics Committee of the Faculty of Medicine. As this is retrospective chart review, patient confidentiality is unlikely to be breached.
All study participants will only be identified by their hospital identification number - KZ numbers will be stored in a secure password-protected database.
APPENDIX B. Ethical Certificate
APPENDIX C. BREC Letter
APPENDIX D. DOH Letter of approval
APPENDIX E: Graphs, Tables, Figures
E 1.0 Age Group
E2.0 Mechanism of Injury Distribution
E3.0 Gender
E 4.0 Length of Stay
E5.Number of Regions Injured (#RI)
