Assessing external cause of injury coding accuracy for transport injury hospitalizations.

External cause of injury codes (E codes) capture circumstances surrounding injuries. While hospital discharge data are primarily collected for administrative/billing purposes, these data are secondarily used for injury surveillance. We assessed the accuracy and completeness of hospital discharge data for transport-related crashes using trauma registry data as the gold standard. We identified mechanisms of injury with significant disagreement and developed recommendations to improve the accuracy of E codes in administrative data. Overall, we linked 2,192 (99.9 percent) of the 2,195 discharge records to trauma registry records. General mechanism categories showed good agreement, with 84.7 percent of records coded consistently between registry and discharge data (Kappa 0.762, p < .001). However, agreement was lower for specific categories (e.g., ATV crashes), with discharge records capturing only 70.4 percent of cases identified in trauma registry records. Efforts should focus on systematically improving E-code accuracy and detail through training, education, and informatics such as automated data linkages to trauma registries.