The estimated survival probability index of trauma severity.

An index of survival rates associated with ICDA injury codes was constructed with data from the 1973 Hospital Discharge Survey (HDS). Discharge records from three regions covered by the HDS allowed estimation of survival rates among patients suffering single injuries coded under 92 ICDA integers. These estimated rates were then applied to records from the fourth HDS region, including those for patients suffering multiple injuries: estimated survival probability index values were generated as the product of the single-condition survival rates for each patient's various injuries. Mortality rates predicted from the index values correlated well with mortality rates estimated for the universe of patients discharged in 1973 from the fourth region. The index is intended for retrospective analysis of discharge records as a possible approach to care evaluation.