Misclassification of Pelvic Ring Injuries in the National Trauma Data Bank

Background: The American College of Surgeons has advocated for all trauma centers to participate in the National Trauma Data Bank (NTDB); however, no previous study has evaluated the accuracy of coding included in this data bank. The purpose of this study was to determine whether pelvic ring injuries are coded accurately in the NTDB and, if not, how they were misclassified. Methods: A retrospective review of all pelvic ring injuries based on Abbreviated Injury Scale (AIS) codes was performed at a single level I academic trauma center from July 2010 to June 2013. Thin-section computed tomography (CT) scans in all patients were reviewed and classified using AIS codes: posterior arch intact, incomplete posterior arch, or complete posterior arch. The surgeon was blinded to the AIS code from the registry. These CT-based classifications were then compared with the pelvic ring injury codes designated in the trauma registry for each patient to evaluate agreement. Results: Two hundred thirty-five patients with a mean age of 42 years had pelvic ring injuries in our registry. The agreement between trauma registry codes and CT reclassification was 24% in the intact group, 43% in the incomplete group, and 59% in the complete group. Using only the trauma registry codes, injuries were underclassified in 48% of the incomplete group and 76% of the intact group. Conclusions: Many pelvic ring injuries are miscoded and misclassified in the NTDB. The etiology of this misclassification is unclear, but any research data mined from these databases should be regarded cautiously.