Mortality Prediction Using Trauma Scores

Trauma remains a leading cause of morbidity and mortality worldwide, with millions of individuals affected annually. The severity of trauma injuries can vary widely, ranging from minor to life-threatening, and effective management often hinges on the ability to quickly assess the severity of injury and predict patient outcomes, including mortality. Accurate and timely prognostication is essential for prioritizing care, guiding treatment decisions, and allocating resources in trauma care settings. Trauma severity scoring systems have been developed to assist in these assessments, with the most commonly used being the Injury Severity Score (ISS), the New Injury Severity Score (NISS), the Revised Trauma Score (RTS), and the Trauma and Injury.

Injury Severity Score (ISS) The Injury Severity Score (ISS) was developed in the 1970s as a way to quantify the severity of trauma-related injuries based on anatomic regions of injury. The ISS assigns scores to the most severe injuries in six body regions, and the sum of the squares of the highest AIS (abbreviated Injury Score) from each of the three most severely injured regions determines the total score. ISS is widely used for risk stratification in trauma patients and has been validated as a predictor of mortality in various populations.

New Injury Severity Score (NISS) The New Injury Severity Score (NISS), introduced in the 1990s, improves upon the ISS by utilizing the three most severe injuries across any body region rather than restricting it to the highest injuries from three predefined regions. Research has shown that NISS is more predictive of mortality than ISS, particularly in patients with polytrauma or multiple severe injuries across different body regions. Despite its advantages, Revised Trauma Score (RTS) The Revised Trauma Score (RTS) is a physiological scoring system based on three clinical parameters: Glasgow Coma Scale (GCS), systolic blood pressure (SBP), and respiratory rate (RR). Unlike ISS and NISS, RTS focuses on the immediate physiological status of the patient rather than the anatomical severity of the injuries. The RTS has been widely used in trauma centers, especially for triage purposes, as it can be quickly assessed in the pre-hospital setting. However, RTS does not account for the type, distribution, or severity of injuries, which can limit its ability to predict mortality in more complex trauma cases.

Trauma and Injury Severity Score (TRISS) The Trauma and Injury Severity Score (TRISS) combines the ISS (or NISS), the RTS, and the patient's age to estimate the probability of survival. TRISS has been widely validated and used in trauma registries as a comprehensive scoring system, considering both injury severity and physiological status. It has been shown to predict trauma-related mortality with good accuracy and is often used to assess trauma system performance and to guide clinical decision-making. However, TRISS may be less accurate in certain populations, such as older adults or those with significant comorbidities, as it primarily relies on injury-related factors and may not fully capture the complex interplay of clinical variables affecting outcomes.

Need for Comparative Studies While individual trauma scoring systems have demonstrated utility in predicting mortality, no single scoring system is universally superior. In clinical practice, there is a need to evaluate and compare these scoring systems across different populations and settings, particularly to determine which system is most reliable in predicting mortality for various trauma mechanisms.

injury patterns, and patient characteristics. Some studies have suggested that combining these systems may improve predictive accuracy, but evidence supporting the superiority of one over the others is inconclusive.

Additionally, while many studies have focused on the predictive validity of these scores in large datasets, fewer studies have compared them head-to-head within the same cohort of trauma patients. This gap in the literature necessitates a comprehensive, cohort-based study that directly compares the performance of the ISS, NISS, RTS, and TRISS for predicting mortality across a broad spectrum of trauma patients.

Inclusion criteria

• Trauma patients admitted to the emergency room (ER).
• Documented injury data sufficient to calculate both the New Injury Severity Score (NISS) and the Injury Severity Score (ISS).
• Trauma scores (ISS, NISS, Revised Trauma Score [RTS], and Trauma and Injury Severity Score [TRISS]) calculated within 12 hour of arrival to ensure timely predictions.
• Informed consent provided by the patient or a legal guardian in cases of incapacity.

Exclusion criteria

• Under 18 years of age and pregnant women, due to differences in trauma management and scoring applicability.
• Non-trauma cases, including patients with terminal illnesses or severe cognitive impairments, to maintain focus on trauma outcomes.
• Incomplete trauma scoring, missing or incomplete medical records, and
• patients not treated in the trauma or emergency department.
• Patients who refuse participation or withdraw consent to ensure ethical participation.
• Transferred patients and those enrolled in other research studies that could interfere with trauma scoring.