The Injury Severity Score (ISS) is a widely used means of describing the overall severity of injury in patients with multiple or single injuries. It is based on the Abbreviated Injury Scale (AIS), a carefully developed method of assigning numerical values to individual injuries, using anatomical diagnoses from discharge records. The ISS correlates well with mortality but has not been specifically evaluated for use with pediatric patients. A pilot study is proposed for testing the predictive validity of the ISS for children, using a database of 1093 children age 0-15 who died or were discharged from Maryland hospitals in 1982. Using logistic regression, the correlation between mortality and ISS and the effect on outcome of age and other variables (such as head injury) will be analyzed. The ISS will be compared with other methods of calculating an overall severity score based on AIS values, to determine which is the best predictor of mortality in children. Pediatric trauma surgeons will be asked to review the 1985 AIS and assess its face validity, with special attention to whether each injury score appears to have approximately the same effect on mortality as other injuries with the same AIS value. This study should provide a better understanding of pediatric trauma outcome as related to injury severity and other factors. Possible modification of the AIS and ISS for use with pediatric populations can be guided by the outcome of this investigation.