Adapting a Clinical Data Repository to ICD-10-CM through the use of a Terminology Repository

Abstract

Clinical data repositories frequently contain patient diagnoses coded with the International Classification of Diseases, Ninth Revision (ICD-9-CM). These repositories now need to accommodate data coded with the Tenth Revision (ICD-10-CM). Database users wish to retrieve relevant data regardless of the system by which they are coded. We demonstrate how a terminology repository (the Research Entities Dictionary or RED) serves as an ontology relating terms of both ICD versions to each other to support seamless version-independent retrieval from the Biomedical Translational Research Information System (BTRIS) at the National Institutes of Health. We make use of the Center for Medicare and Medicaid Services' General Equivalence Mappings (GEMs) to reduce the modeling effort required to determine whether ICD-10-CM terms should be added to the RED as new concepts or as synonyms of existing concepts. A divide-and-conquer approach is used to develop integration heuristics that offer a satisfactory interim solution and facilitate additional refinement of the integration as time and resources allow.

Figure 1:

A sample of concepts in the RED hierarchy. The concept “Acute Hemolytic Reaction – Grade 1” corresponds to a term from the system in the Clinical Center’s Department of Transfusion Medicine, while “Acute Hemolytic Transfusion Reaction, Incompatibility Unspecified” corresponds to the I9 term with the code 999.84. Note that a BTRIS user wishing to retrieve data about acute hemolytic reactions can simply request the parent concept, “Acute Hemolytic Transfusion Reaction” and data coded by all three concepts will be retrieved.

Figure 2:

Understanding the General Equivalence Mapping Codes. Examples of the I10 to I9 GEM mappings are shown, with interpretation of each of the five flag positions. Note that GEM mapping files do not include term names; these were added here for clarity.

Figure 3:

Example of a RED concept that maps to an I9 term and an I10 – that is, the terms are considered synonymous. This is also a term used by an NIH clinical trials data management system (CRIMSON).

Figure 4:

Example of RED hierarchy after inclusion of I10 terms. Light boxes represent concepts that were in the RED prior to inclusion of I10 terms; dark boxes represent newly added concepts. I9 and I10 codes are shown in {curly braces}.