Vocab. ICD10PCS

Overview

The ICD-10 Procedure Coding System (ICD-10-PCS) is a US system of medical classification used for procedural coding. It was developed for the Centers for Medicare and Medicaid Services (CMS). CMS is the US governmental agency responsible for overseeing all changes and modifications to the ICD-10-PCS.

Sources

In OMOP we use the following sources for ICD10PCS vocabulary:

1. The source data provided by the Centers for Medicare and Medicaid Services (CMS) contains information about valid procedure codes.
2. The UMLS source contains the developed internal hierarchy of ICD10PCS. All ICD10PCS Hierarchy concepts and their relationships originate from the UMLS source.

Transformation

The procedures for transforming Concepts from the source to the OMOP Standard Vocabularies can be found on the OHDSI GitHub.

Concept Names

All ICD10PCS Concepts are assigned the names provided by the CMS source. When a concept is deprecated by the source the note “(Deprecated)” is added at the end of its name.

Names for the ICD10PCS Hierarchy concepts are assigned according to the Hierarchical Term descriptions provided by the UMLS. However, ICD10PCS Hierarchy concepts that refer to the XW0 section, especially first-degree ancestors of drug administration procedures, demonstrate high variability of concept names. This behavior depends both on the intrinsic vocabulary logic (X-codes are assigned to the new or experimental technologies and are refreshed often so that the same ancestor may have different descendants in each vocabulary release) and the UMLS logic of concept name compilation (names are assembled from distinct values of ICD10PCS source files with @ symbol as separators, and these values may vary). To avoid redundant variability and subsequent confusion we decided to replace the last variable part of XW0 hierarchical concepts that refer to drug administration procedures with a placeholder ‘@ Drug administration’.

Concept Code

All ICD10PCS concept codes are assigned according to the codes provided by the sources.

ICD10PCS codes are alphanumeric and seven characters long. Each digit refers to a specific semantic category.

ICD10PCS Hierarchy concept codes are created by the UMLS, they are also alphanumeric but their length is less than seven characters and depends on the hierarchy level.

Standard Concepts

ICD10PCS concepts are standard by default. Concepts that refer to drug administration are mapped to standard concepts in the Drug domain and de-standardized.

Domains

All ICD10PCS concepts are in the Procedure domain by default.

Concepts that represent drug administration procedures and could be mapped to standard concepts in the Drug domain are manually moved to the Drug domain.

Concepts that carry the semantics of blood product administration belong to the Device domain.

Concept Classes

The ICD10PCS concepts are composed of the following Concept Classes:

Class	Notes
ICD10PCS	These codes are used for coding procedures associated with hospital utilization in the United States.
ICD10PCS Hierarchy	Hierarchical codes developed by the UMLS to create the internal hierarchy of ICD10PCS.

Concept Relationships

Hierarchy

ICD10PCS has a multi-level internal hierarchy sourced from the UMLS. Additionally, we create the hierarchical (‘Is a’) relationships from ICD10PCS to SNOMED with the help of the automated process which uses an attributive approach to create hierarchical relationships. The primary purpose is to create a unified hierarchy of procedures based on the SNOMED/OMOP extension hierarchy.

Mapping

ICD10PCS concepts are standard by default and therefore map to themselves.

Concepts that represent the administration of drugs are mapped to standard concepts in the Drug domain if they can be properly mapped. In the absence of a proper mapping target, ICD10PCS concepts remain standard in the Procedure domain.