ICD Injury Codes and Matrices

What are International Classification of Diseases (ICD) codes?

The International Classification of Diseases (ICD) is a classification system developed by the World Health Organization to assist in international comparisons of causes of mortality, and includes codes for various diseases, disorders, injuries, and other health conditions. The system was originally developed to categorize deaths; however, several countries have developed more detailed clinical modifications of the classification system for use with nonfatal data. The classification systems are periodically updated resulting in multiple revisions.

For mortality data, the most recent revisions include:

For morbidity data, the most recent revisions include:

What are injury diagnosis codes?

The injury diagnosis codes (or nature of injury codes) are the ICD codes used to classify injuries by body region (for example, head, leg, chest) and nature of injury (for example, fracture, laceration, solid organ injury, poisoning).

What are external cause of injury codes?

Two components are described in the external cause of injury: 1) the vector that transfers energy to the body (for example, fall, motor vehicle traffic accident, burns, poisoning), and 2) the intent of the injury (that is, whether the injury was inflicted purposefully and by whom [self or another person]). For deaths, the intent is also sometimes referred to as the “manner of death.”

The external cause-of-injury codes are the ICD codes used to classify injury events by mechanism and intent of injury. Intent of injury categories include unintentional, homicide/assault, suicide/intentional self-harm, legal intervention or war operations, and undetermined intent.

What are the matrices?

The ICD injury matrices are frameworks designed to organize ICD coded injury data into meaningful groupings. The matrices were developed to facilitate national and international comparability in the presentation of injury statistics.

There are two general types of injury matrices:

• Injury diagnosis matrices use ICD diagnosis codes to group injuries by the body region and nature of injury, and
• External cause matrices use ICD external cause codes to group injuries by the mechanism and intent of injury.

Injury diagnosis matrices have been developed for use with ICD–9–CM (the Barell Matrix), ICD–10 (the Injury Mortality Diagnosis Matrix), and ICD–10–CM (the ICD–10–CM Injury Diagnosis Matrix).

External cause matrices have been developed for use with ICD–9, ICD–9–CM, ICD–10, and ICD–10–CM.

For more information on injury diagnosis matrices, visit:

ICD–10–CM

Hedegaard H, Johnson RL, Garnett MF, Thomas KE. The 2020 International Classification of Diseases, 10th Revision, Clinical Modification injury diagnosis framework for categorizing injuries by body region and nature of injury. National Health Statistics Reports; no 150. Hyattsville, MD: National Center for Health Statistics. 2020. Available from: https://www.cdc.gov/nchs/data/nhsr/nhsr150-508.pdf

Hedegaard H, Johnson RL, Warner M, Chen L-H, Annest JL. Proposed framework for presenting injury data using the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD–10–CM) diagnosis codes. National Health Statistics Reports; no 89. Hyattsville, MD: National Center for Health Statistics. 2016. Available from: https://www.cdc.gov/nchs/data/nhsr/nhsr089.pdf

ICD–10

Fingerhut LA, Warner M. The ICD–10 injury mortality diagnosis matrix. Inj Prev 12(1):24–9. 2006. Available from: https://injuryprevention.bmj.com/content/12/1/24.

ICD–9–CM

Barell V, Aharonson-Daniel L, Fingerhut LA, MacKenzie EJ, Ziv A, Boyko V, et al. An introduction to the Barell body region by nature of injury diagnosis matrix. Inj Prev 8(2):91–6. 2002. Available from: https://injuryprevention.bmj.com/content/8/2/91.

For more information on external cause of injury matrices, visit:

ICD–10–CM

Hedegaard H, Johnson RL, Garnett MF, Thomas KE. The International Classification of Diseases, 10th Revision, Clinical Modification (ICD–10–CM) external cause-of-injury framework for categorizing mechanism and intent of injury. National Health Statistics Reports; no 136. Hyattsville, MD: National Center for Health Statistics. 2019. Available from: https://www.cdc.gov/nchs/data/nhsr/nhsr136-508.pdf.

Annest J, Hedegaard H, Chen L, Warner M, and Small E. Proposed framework for presenting injury data using ICD–10–CM external cause of injury codes. Atlanta, GA: National Center for Injury Prevention and Control, National Center for Health Statistics, Centers for Disease Control and Prevention. 2014. Available from: https://www.cdc.gov/injury/wisqars/pdf/ICD-10-CM_External_Cause_Injury_Codes-a.pdf.

ICD–10

National Center for Health Statistics. External cause of injury mortality matrix. Hyattsville, MD. 2015. Available from: /nchs/injury/injury_matrices.htm.

ICD–9 and ICD–9–CM

Centers for Disease Control and Prevention. Recommended framework for presenting injury mortality data. MMWR 46(RR14):1–30. 1997. Available from: https://www.cdc.gov/mmwr/preview/mmwrhtml/00049162.htm.

See also: https://www.cdc.gov/injury/wisqars/ecode_matrix.html

ICD codes for matrices and SAS statements

For ICD codes for each of the matrices and SAS statements and formats for data analysis, see Tools for Classifying ICD Codes.