Abstract
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.