The injury severity score of road traffic casualties in relation to mortality, time of death, hospital treatment time and disability

The similarity of the mortality relationship to that for burns suggests that both the I.S.S.'s and surface area of burn are comparable measures of the lethality of injury and the Probit fits suggest that at given ages there are normal distributions of susceptibility.

Abstract

The I.S.S. rating for 1333 road accident casualties admitted to hospital showed; (1) a positive relation to mortality amenable to Probit analysis and higher mortalities with advancing years. (2) A trend of negative association with time to death. (3) Separation of survivors into groups with statistically distinct mean treatment times. (4) Significantly different mean I.S.S. ratings with different severities of residual disability. The similarity of the mortality relationship to that for burns suggests that both the I.S.S. and surface area of burn are comparable measures of the lethality of graded injury. The Probit fits suggest that at given ages there are normal distributions of susceptibility. There is a wide scatter of treatment times and severities of disability for given scores. Average expected values can be derived for groups of cases but the I.S.S. of a single casualty has little prognostic significance. There is scope for improvement in the I.S.S. procedure but even in its present form more extended use would establish norms more securely.