With approval from the American Hospital Association (AHA) and American Health Information Management Association (AHIMA), the Centers for Medicare & Medicaid Services (CMS) and the National Center for Health Statistics (NCHS) publish annual ICD-10-CM coding guidelines that provide HIPAA-required instructions for assigning ICD-10-CM codes.
While there is no national or North Carolina requirement that hospital coders include ICD-10-CM external cause codes for injury-related encounters, nor are these codes reimbursable for billing, the coding guidelines include guidance on injury mechanism coding (see pages 85-90). This includes how to code for injuries where the intent is unknown or undetermined:
Page 88: h. Unknown or Undetermined Intent Guideline
If the intent (accident, self-harm, assault) of the cause of an injury or other condition is unknown or unspecified, code the intent as accidental intent. All transport accident categories assume accidental intent.
- Use of undetermined intent
External cause codes for events of undetermined intent are only for use if the documentation in the record specifies that the intent cannot be determined.
As part of annual updates to ICD-10-CM codes and guidance reviewed by the ICD-10-CM Coordination and Maintenance Committee, there is a proposal to update the Unknown or Undetermined Intent Guideline section specifically for firearm injuries (see pages 43-44).
Option #1 would change the default intent from “accidental” to “assault” for all firearm injuries when the intent is unknown or unspecified. This option also includes changing the code listed in the Alphabetic Index for External Causes for “gunshot wound” from “W34, accident by unspecified firearm,” to “X95.9, assault by unspecified firearm.”
Option #2 would change the default intent from “accidental” to “undetermined” for all firearm injuries when the intent is unknown or unspecified. This option also includes changing the code listed in the Alphabetic Index for External Causes for “gunshot wound” from “W34, accident by unspecified firearm,” to “Y24.9, Unspecified firearm discharge, undetermined intent.”
Based on our work with NC-FASTER, we recognize that external cause coding for firearm injuries currently overestimates the number of emergency department visits for unintentional firearm injury and that current coding guidelines contribute to this issue. While the Option #1 proposal submitted to ICD-10-CM Coordination and Maintenance Committee suggests that nonfatal assault-related firearm injuries represent as many as 80% of all nonfatal firearm injuries, we are unsure that this percentage accurately reflects all nonfatal firearm injury, as these estimates were based on trauma center data or nationally sampled data of a relatively small number of hospitals. In a manual review of 1,475 NC ED visits identified as firearm injury in 2019 and 2020 we could not determine intent for 71.2% of ED visits, while only 8.2% were identified as assault. In an additional manual review of all NC emergency medical services (EMS) encounters for firearm-related injuries in 2021 and 2022, we found that 52% of all EMS encounters were assault-related, and, more specifically, 58% of nonfatal EMS encounters transported to an ED were assault-related.
If the default intent for firearm injury changes from accidental to assault, the number of emergency department visits for assault-related firearm injury will be overestimated. Replacing one type of misclassification with another does not solve the ICD-10-CM coding problem regarding firearm injury intent. Additionally, assigning assault intent to firearm injuries that are not assaults may result in unintended harms, such as victim blaming and potential misallocation of resources for tailored prevention programs.
As such, we believe that Option #2, assigning undetermined intent for firearm injuries when the cause is unknown or unspecified, is the more appropriate update for coding firearm injuries. When ICD-9-CM was the coding standard, the guidance was to default to undetermined so there is a precedent for this approach.
If you have an opinion on the proposed changes, the ICD-10-CM Coordination and Maintenance Committee is accepting comments on these two proposals now until November 15, 2023 via email at firstname.lastname@example.org.
If you have questions about using NC DETECT for firearm-related injury, please contact us at email@example.com.
The North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT) is an advanced, statewide public health surveillance system. NC DETECT is supported by the North Carolina Division of Public Health through a federal Public Health Emergency Preparedness Grant and is managed through a collaboration between NC DPH and the University of North Carolina at Chapel Hill Department of Emergency Medicine’s Carolina Center for Health Informatics. The findings and conclusions in this post are those of the author(s) and do not necessarily represent the views of the North Carolina Department of Health and Human Services, Division of Public Health.