The International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) External Cause-of-injury Framework for Categorizing Mechanism and Intent of Injury.

Background-External cause-of-injury frameworks, or matrices, based on the International Classification of Diseases (ICD) provide standardized categories for reporting injuries by mechanism and intent of injury. In 2014, the National Center for Health Statistics (NCHS) and the National Center for Injury Prevention and Control (NCIPC) published a proposed external cause-of-injury matrix for use with data coded using the ICD, 10th Revision, Clinical Modification (ICD-10-CM). At the time the proposed matrix was developed, ICD-10-CM coded data were not available to evaluate the performance of the proposed matrix. When data became available, NCHS and NCIPC collaborated with the Council of State and Territorial Epidemiologists and state and local health departments to evaluate the proposed matrix to identify any changes needed before finalization. This report describes the results of that evaluation. Methods-With guidance from NCHS and NCIPC, state and local injury epidemiologists from five jurisdictions analyzed their hospital discharge and emergency department administrative claims data. The epidemiologists applied the ICD-9-CM matrix to ICD-9-CM coded data and the 2014 proposed ICD-10-CM matrix to ICD-10-CM coded data for similar time periods (e.g., January through December). The numbers for each mechanism and intent category in each of the two matrices were calculated and compared, and major differences were explored. Results-Based on the findings, several adjustments were made to the original placement of codes in the 2014 proposed ICD-10-CM external cause-of-injury matrix. These changes involved codes related to Drowning/submersion, Firearm, Motor vehicle-Traffic, Overexertion, and Unspecified mechanisms. In addition, new external cause codes not available at the time the 2014 proposed matrix was developed were added to create the 2019 final matrix. Conclusions-The 2019 final ICD-10-CM external cause-of-injury matrix provides standard categories for reporting injuries by mechanism and intent of injury. Use of this tool promotes consistency for comparisons across populations and over time.