Comparison of Trauma and Injury Severity Score model with alternative approach in outcome prediction in trauma using National Trauma Database in Malaysia

Objective

The coefficients for the Trauma and Injury Severity Score are derived from the Major Trauma Outcome Study (MTOS) in North America, so the applicability of the MTOS-Trauma and Injury Severity Score (TRISS) in different populations remains challenging. This study proposed an alternate TRISS model called National Trauma Database-TRISS, where the coefficients were derived from the National Trauma Database (NTrD) in Malaysia.

Methods

This study utilised data derived from the National Trauma Database in Malaysia with 70% of the cases being used to develop the NTrD-TRISS model, while model validation was conducted based on the remaining 30% of cases. Fractional polynomial method was applied to correct the non-linearity in the logit of Injury Severity Score (ISS) and New Injury Severity Score (NISS). The predictive validity of the NTrD-TRISS model was compared with the MTOS-TRISS model. The predictive validity of these models was further examined with ISS and NISS.

Results

A total of 5857 major trauma cases reported to 13 trauma centres located throughout Malaysia for patients aged 16 and above were included in the study. The outcome prediction in trauma from NTrD-TRISS model was found to be more accurate compared to the MTOS-TRISS model.

Conclusions

This study has ascertained the applicability of the MTOS-TRISS model in Malaysia. The outcome prediction in trauma from the NTrD-TRISS was found to outperform the MTOS-TRISS model. Given the complex computational nature of ISS, the MTOS-TRISS and NTrD-TRISS models with NISS were recommended for future practical usage.

The role of trauma scoring in developing trauma clinical governance in the Defence Medical Services

This paper discusses mathematical models of expressing severity of injury and probability of survival following trauma and their use in establishing clinical governance of a trauma system. There are five sections: (i) Historical overview of scoring systems--anatomical, physiological and combined systems and the advantages and disadvantages of each. (ii) Definitions used in official statistics--definitions of 'killed in action' and other categories and the importance of casualty reporting rates and comparison across conflicts and nationalities. (iii) Current scoring systems and clinical governance--clinical governance of the trauma system in the Defence Medical Services (DMS) by using trauma scoring models to analyse injury and clinical patterns. (iv) Unexpected outcomes--unexpected outcomes focus clinical governance tools. Unexpected survivors signify good practice to be promulgated. Unexpected deaths pick up areas of weakness to be addressed. Seventy-five clinically validated unexpected survivors were identified over 2 years during contemporary combat operations. (v) Future developments--can the trauma scoring methods be improved? Trauma scoring systems use linear approaches and have significant weaknesses. Trauma and its treatment is a complex system. Nonlinear methods need to be investigated to determine whether these will produce a better approach to the analysis of the survival from major trauma.