This section includes two parts: a glossary of common terms and their abbreviations and an explanation of ICD-10-CM concepts. These are presented in the two tables below.

Glossary of Terms and Abbreviations




CDC State Injury Indicators


The State Injury Indicators (SII) are a series of indicator recommendations published by CDC and used by state health departments to calculate and report injury.

Contributing Cause


This term is formally used to refer to specific fields on the death certificate in mortality data. It is sometimes informally applied to nonfatal hospitalization data to refer to diagnoses other than the principal diagnosis, however this is discouraged. While contributing cause has meaning in mortality data, it should NOT be used to refer to diagnoses other than the principal diagnosis.

Council of State and Territorial Epidemiologists


CSTE is an organization of member states and territories representing public health epidemiologists, working to advance public health surveillance policy and epidemiologic capacity to conduct sound public health surveillance.

CSTE Policy Briefs


CSTE policy briefs describe CSTE positions on public health and epidemiologic issues. CSTE policy briefs can suggest policy action(s) that does not affect state or local law/rule/regulation, provide guidance for best practices, state support for specific policies or guidelines from other organizations or endorse positions taken by other organizations, etc.

CSTE Position Statements


CSTE position statements describe standardize surveillance case definitions, maintain the Nationally Notifiable Condition List that states must report to CDC, and address policy issues that could affect state or local law, rules or regulations. CSTE members can write and submit CSTE position statements each spring and then the CSTE membership discuss, revise and vote on position statements at the Annual Conference in June. CSTE position statement authors must be active CSTE members, although associate members (such as staff from federal agencies) may be co-authors

CSTE Issue Briefs


CSTE issue briefs identify, define, and explain issues. Issue briefs can be statements of fact about an issue, provide CSTE’s opinion or perspective on an issue, summarize a meeting or the results of an assessment with its implications, present the state of a content area or condition, provide an overview of a topic, etc.

Emergency Department Data


Medical billing data collected from ED visits. 

External Cause of Injury Codes


V, W, X and Y codes found in Chapter 20 of the ICD-10-CM used to describe the mechanism and intent of the injury.  External cause of injury information is also included in some T codes found in Chapter 19 (see Table 2 in the “Data Quality Measures for ICD-10-CM Hospitalizations and ED Visits” document found here). In addition to codes describing mechanism and intent of injury, ICD-10-CM Chapter 20 also includes codes for place of occurrence, activity, alcohol involvement (blood alcohol level), and work status at time of injury.  

External Cause of Injury Matrix


The external cause of injury matrix describes the mechanism that transfers the energy (force) to the body (e.g. fall, motor vehicle traffic accident, or poisoning) and the intent of the injury (e.g. whether the injury was inflicted purposefully).

Hospitalization Data


Medical billing data collected from hospitalizations. 

ICD Injury Matrices


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

Injury Diagnosis Codes


ICD-10-CM (S and T codes from Chapter 19 of the ICD-10-CM) used to describe the injury by the nature of an injury (burns, sprains, etc.) and the body region (extremity, head, etc.).

Injury Diagnosis Matrix


The injury diagnosis matrix describes the resulting injury by nature of an injury (burns, sprains, etc.) and the body region.

International Classification of Diseases


A set of medical codes and related codes determined by the World Health Organization (WHO)

International Classification of Diseases, Ninth Revision


The version of the World Health Organization’s (WHO) International Classification of Diseases (ICD) used in the U.S. for mortality statistics from 1979-1998.

International Classification of Diseases, Tenth Revision


For mortality statistics, ICD-10 is the standard for international comparison for causes of deaths. ICD-10 is published by the World Health Organization (WHO).  The U.S. adopted ICD-10 for mortality data in 1999.

International Classification of Diseases – Ninth Revision – Clinical Modification


The US Centers for Medicare and Medicaid Services publishes the Clinical Modifications of the ICD for use with medical provider data. The ICD-9-CM was used to code US medical provider data from 1979 until October 1, 2015.

International Classification of Diseases, Tenth Revision, Clinical Modification


The US Centers for Medicare and Medicaid Services publishes the Clinical Modifications of the ICD for use with medical provider data. The ICD-10-CM was implemented in the U.S. on October 1, 2015.

National Center for Health Statistics


Also known as NCHS, this Center is the principal health statistics agency of the Centers for Disease Control and Prevention and for the nation—collecting and analyzing healthcare data.

National Center for injury Prevention and Control


Also known as NCIPC, this Center tracks injuries and deaths, researches injury and violence prevention strategies, develops and evaluates prevention strategies, and supports the implementation of programs.

Principal Diagnosis


Hospital Discharge Data contains a principal diagnosis which identifies the primary reason for the encounter of inpatient care. (Also sometimes referred to as primary diagnosis.)  The US ICD-10-CM coding manual specifies which codes can be a principal diagnosis. Note: Emergency department data does not contain a principal diagnosis field.



Open source software environment for statistical computing and graphics that is available on a wide variety of platforms, including Windows and MacOS. R provides an ever-expanding library of statistical (linear and nonlinear modeling, classic statistical tests, time-series analysis, classification, clustering, …) and graphical techniques.12

Seventh (7th) character of ICD-10-CM code

E.g.  S12.9XXA

This character of the ICD-10-CM code identifies the type of encounter when the diagnosis was made. A seventh character of “A”, “B”, or “C” is used for initial encounters for medical care. A seventh character of “D” through “R” is used for subsequent medical encounters. A seventh character of “S” is for a sequela of an injury event, such as complications and/or conditions resulting from an injury.

For External Cause: A: Initial encounter; D: Subsequent encounter; S: Sequelae. For Injury Diagnosis: A, B, C: Initial encounter; D through R: Subsequent encounter; S: Sequelae.

Underlying Cause


This term is formally used referring to a specific field on the death certificate.  This field must contain an external cause of injury code to be considered an injury death.



The process of establishing that a method is sound, that is, the method leads to unbiased results. In epidemiology, external validity is often described as generalizable to a population.13

Valid methods


Unbiased methods, such that on average results are close to the truth.14

Web-based Injury Statistics Query and Reporting System


An interactive, online database that provides fatal and nonfatal injury, violent death, and cost of injury data from a variety of trusted sources. Researchers, the media, public health professionals, and the public can use WISQARS™ data to learn more about the public health and economic burden associated with unintentional and violence-related injury in the United States.

Wide-ranging Online Data for Epidemiologic Research


An easy-to-use, menu-driven system that makes the information resources of the Centers for Disease Control and Prevention (CDC) available to public health professionals and the public at large. It provides access to a wide array of public health information.




Explanation of Concepts



Any Mention of Valid External cause of injury codes

Records can have more than one external cause of injury code.  For surveillance purposes, it is important to consider whether to classify the case using only the first code that contains external cause of injury information or to classify the case using “any mention” of an external cause code (an external cause code in any field). The “any mention” approach can result in a case being counted in more than one category if multiple codes with external cause of injury information are present. 

Injury diagnosis codes that convey external cause information

In ICD-10-CM, there are several T codes that provide both diagnosis and external cause information. These codes are used both for selecting cases and for categorizing cases by external cause. As of 2019, the T codes that provide both diagnosis and external cause information include T14.91, T15-T19, T36-T50 with a 6th character of 1, 2, 3, or 4 (except T36.9, T37.9, T39.9, T41.4, T42.7, T43.9, T45.9, T47.9, and T49.9 which are included if they have a 5th character of 1, 2, 3, or 4), T51-T65, T71, T73, T74, T76, T75.0, T75.1, T75.2, and T75.3.

Healthcare Billing data

Data whose purpose is to bill for reimbursement of healthcare or treatment. In the US, these data are based on the Uniform Billing standard established in 2004 and the form is often described as UB-04. Health plans reimburse for the procedures, not for the diagnoses, which are included only to justify the procedures. UB-04 is further described in the appendix.

Injury Hospitalization Datasetp>

A subset of all hospitalizations where the principal diagnosis (i.e. first listed diagnosis code) is an injury. This indicates that the primary reason for the encounter of inpatient care was for an injury.

Key of Three

A set of correct answers based on at least three programing approaches to querying the validation dataset (e.g. three different programmers run the validation dataset with their own program and all result in the same answers). The project specific “Key of Three” then becomes the measuring stick for programing accuracy.

Regular expressions

Regular expression is a pattern that describes a specific set of strings with a common structure. It is heavily used for string matching / replacing in all programming languages, although specific syntax may differ a bit. It is the heart and soul for string operations.


Regular expressions typically specify characters (or character classes) to seek out, possibly with information about repeats and location within the string. This is accomplished with the help of metacharacters that have specific meaning: $ * + . ? [ ] ^ { } | ( ) \.

Secondary data analysis

Analysis using data created for a different purpose than the purpose of the secondary analysis. For example, public health staff can conduct secondary data analysis of healthcare billing data in order to monitor injuries that receive medical care.

Validation of proposed surveillance methods

The testing of the definitions and frameworks to assist in the standardization of results (often across jurisdictions and time) for comparison purposes. There are different methods for testing, such as a medical record review.

Validation of programming code

Standardized datasets, such as the Validation Datasets included in this toolkit, are fictional datasets with known answers that can be used to test programming code and ensure that users will obtain the correct answers. This validated programming code can later be used to implement the surveillance methods described above.