Assessment of probability of survival in penetrating injuries using the TRISS methodology

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.

Trauma survival prediction in Asian population: a modification of TRISS to improve accuracy

The probability of survival (PS) in blunt trauma as calculated by Trauma and Injury Severity Score (TRISS) has been an indispensable tool in trauma audit. The aim of this study is to explore the predictive performance of the latest updated TRISS model by investigating the Age variable recategorisations and application of local Injury Severity Score (ISS) and Revised Trauma Score (RTS) coefficients in a logistic model using a level I trauma centre database involving Asian population.

METHODS

Prospectively and consecutively collected 5684 trauma patients' data over a 10-year period at a regional level I trauma centre were reviewed. Four modified TRISS (mTRISS) models using Age coefficient from reclassifications of the Age variable according to their correlation with survival by logistic regression on the local dataset were acquired. RTS and ISS coefficients were derived from the local dataset and then applied to the mTRISS models. mTRISS models were compared with the existing Major Trauma Outcome Study (MTOS)-derived TRISS (eTRISS) model. Model 1=Age effect taken as linear; Model 2=Age classified into two groups (0-54, 55+); Model 3=Age classified into four groups (0-15, 16-54, 55-79, 80+) and Model 4=Age classified into two groups (0-69, 70+). Performance measures including sensitivity, specificity, accuracy and area under the Receiver Operating Characteristic (ROC) curve were used to assess the various models. The cross-validation procedure consisted of comparing the P(S) obtained from mTRISS Models 1 and 2 with the P(S) obtained from the MTOS derived from eTRISS.

RESULTS

A 5147 blunt trauma patients' dataset was reviewed. Model 1, where Age was taken as a scale variable, demonstrated a substantial improvement in the survival prediction with 91.6% accuracy in blunt injuries as compared with 89.2% in the MTOS-derived TRISS. The 95% CI for ROC derived from mTRISS Model 1 was (0.923, 0.940), when compared with the hypothesised ROC value 0.886 obtained from eTRISS, it clearly indicated a significant improvement in predicting survival at 5% level. Furthermore, ROCs have shown clearly the superiority of Model 1 over Model 2, and of Model 2 over MTOS-derived TRISS. The recategorisation of the Age variable (Models 3 and 4) also demonstrated improved performance, but their strength was not as intense as in Model 1. Overall, the results point to the adoption of Model 1 as the best model for PS. Cross-validation analysis has further assured the validity of these findings.

CONCLUSIONS

The present study has demonstrated that (1) having the Age variable being dichotomised (cut-off at 55 years) as in the eTRISS, but with the application of a local dataset-derived coefficients give better TRISS survival prediction in Asian blunt trauma patients; (2) improved performance are found with certain recategorisation of the Age variable and (3) the accuracy can further be enhanced if the Age effect is taken to be linear, with the application of local dataset-derived coefficients.

The regionalization of pediatric health care

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

Evaluation of Quality of Trauma Care in a Local Hospital Using a Customization of ASCOT

OBJECTIVE

Evaluating processes of care and outcomes of injured patients are important if improvements in the quality of care delivered to injured patients are to be accomplished. We applied a customized ASCOT model developed from our database as a tool to criticize the quality of care in a local hospital.

PATIENTS AND METHODS

A total number of 4,096 trauma patients were used to develop new coefficients for customization of ASCOT. These patients were divided randomly into two equal groups. New coefficients for ASCOT were derived from the first set of patients. The newly developed model was validated in the second group of patients and the measures of discrimination (area under the ROC curve) and calibration (Hosmer-Lemeshow goodness of fit) were calculated. Then we used the customized model to calculate the W score in different subgroups of patients treated in a local hospital to evaluate the care offered to patients in each group.

RESULTS

The customized ASCOT had a good discrimination (area under ROC curve = 0.9575) and calibration (Hosmer-Lemeshow goodness of fit p value = 0.7628) in the validation dataset. Using the customized model, we calculated W score in different subgroup of patients treated in a local hospital for a period of six months. The quality of care was worst for laparotomy (W = -13.31) and pelvic fracture (W = -5.56) and best for orthopedic (W = 1.76) operations.

CONCLUSION

We believe that a customization of ASCOT model when used for evaluation of quality of care in a local hospital can be useful for detection of defects and improvement of the process of care delivered to the patients.

Scoring systems in trauma

BACKGROUND

Trauma is a major cause of mortality and morbidity worldwide. Methods of assessing outcome have evolved with management of trauma victims.

RESULTS AND DISCUSSION

The wide variety of scoring instruments available to assess the injured patient may be divided into three groups: anatomical, physiological and combined systems. Anatomical systems depend on an accurate description of the injuries sustained. Physiological systems measure the effects of injury on the patient's physiological reserves. Combined systems contain elements of both anatomical and physiological scores. Prospectively, scoring systems help in description, triage, treatment decisions and estimating outcome. Retrospective scoring is helpful in audit, in quality control, in comparing treatment methods or centres, and in identifying unexpected outcomes. Limitations may be inherent in the system or may reflect inaccurate or incomplete data collection.

Lethal abdominal gunshot wounds at a level I trauma center: analysis of TRISS (Revised Trauma Score and Injury Severity Score) fallouts

BACKGROUND

The TRISS methodology (composite index of the Revised Trauma Score and the Injury Severity Score) has become widely used by trauma centers to assess quality of care. The American College of Surgeons recommends including negative TRISS fallouts (fatally injured patients predicted to survive by the TRISS methodology) as a filter to select patients for peer review. The purpose of this study was to analyze the TRISS fallouts among patients with lethal abdominal gunshot wounds admitted to a level I trauma center.

STUDY DESIGN

All patients categorized as TRISS fallouts admitted from January 1995 through December 1996 were analyzed.

RESULTS

During the study period, 848 patients with abdominal gunshot wounds were admitted. Of the 108 patients with any sign of life on admission who subsequently died, 39 (36%) were TRISS fallouts. The patients were largely young (mean age, 29 years) and male (87%), received rapid transport (mean scene time, 11 minutes), and had an attending-led trauma-team response (<5 minutes, 87%). Major vascular (80%) and multiple intraabdominal injuries (90%) predominated. The mean Penetrating Abdominal Trauma Index was 40.3. The mean TRISS probability of survival was 89%. The peer-review process deemed the deaths to be nonpreventable in 38 patients (97%) and potentially preventable in one patient (3%).

CONCLUSIONS

"TRISS fallouts" were predominantly patients who died despite receiving rapid prehospital transport, rapid senior-level trauma-team response, and surgical intervention for a serious complex of injuries. We conclude that without regional adjustment of coefficients used to predict the probability of survival, the TRISS methodology is of limited use in patients with abdominal gunshot wounds.

TRISS methodology in penetrating trauma: 198 patients at Baragwanath Hospital

TRISS methodology is a statistical technique by which the probability of survival in injury can be estimated. It combines an anatomical index of injury severity (the injury severity score, ISS), a physiological index (the revised trauma score, RTS), age and the mechanism of injury. In this study TRISS was used to assess 198 patients with penetrating injury at Baragwanath Hospital. One hundred and sixty-two patients had stab wounds, 26 gunshot wounds, and 10 received other injuries. Fifty patients were seriously injured (ISS > 15). Four patients (2%) died. The respective probabilities of survival for these four patients, as derived by TRISS, were 0%, 0%, 6% and 46%. TRISS demonstrated that the outcome of the patients as a group was comparable to other centres. TRISS is a useful method for monitoring the effectiveness of a trauma unit and objectively identifying cases for peer review.