Severity of injury is underestimated in the absence of autopsy verification

Background: Trauma disproportionately affects young, productive citizens. To decrease the preventable death rate and morbidity, and to save society some of the estimated $230 million per day revenue loss attributable to these injuries, trauma systems were developed. New York State instituted a population-based regional trauma registry to enter all patients meeting appropriate International Classification of Diseases, Ninth Revision diagnostic codes. Methods: We evaluated the registry records deaths in a single New York State trauma region. We compared the medical records used for registry entry to the autopsy records from the County Medical Examiner's Office to determine accuracy of diagnostic coding. On the basis of autopsy data, the records were then recoded and the extent of the trauma rescored. Results: One hundred thirty-four deaths from 1993 to 1998 were recorded. Twelve records (9%) were accurately entered. One hundred twenty-two records had 452 errors. The mean Injury Severity Score (ISS), based on the medical record face sheet, was 29.93. The revised ISS, based on autopsy review, was 34.44 (p = 0.0108, two-tailed t test). The 95% confidence interval of the difference was 1.05 to 7.96. Z scores were -14.36 before autopsy review and -13.21 after autopsy review (p = 0.4395, not significant). We demonstrated a significantly higher ISS in the patients who died when the autopsy findings were included for coding. This information was not available from the medical record. Conclusion: To accurately compare trauma center performance and injury severity, the inclusion of autopsy data is critically important. Present state law does not permit sharing of this information with the trauma centers. When comparing mortality rates of New York State trauma centers, data must be carefully interpreted.