Keith E. Campbell

The Unified Medical Language System: Toward a Collaborative Approach for Solving Terminologic Problems

The approach taken by the Unified Medical Language System (UMLS), in which disparate terminology systems are integrated, has allowed construction of an electronic thesaurus (the Metathesaurus) that avoids imposing any restrictions upon the content, structure, or semantics of the source terminologies. As such, the UMLS has served as a unifying paradigm by providing appropriate links among equivalent entities that are used in different contexts or for different purposes. It accordingly provides a vehicle through which possibly orthogonal semantic models can co-exist within a single framework. This framework provides a model for the collaborative evolution of biomedical terminology and allows a synergistic relationship between the UMLS and its source terminology systems.

A Logical Foundation for Representation of Clinical Data

OBJECTIVE A general framework for representation of clinical data that provides a declarative semantics of terms and that allows developers to define explicitly the relationships among both terms and combinations of terms. DESIGN Use of conceptual graphs as a standard representation of logic and of an existing standardized vocabulary, the Systematized Nomenclature of Medicine (SNOMED International), for lexical elements. Concepts such as time, anatomy, and uncertainty must be modeled explicitly in a way that allows relation of these foundational concepts to surface-level clinical descriptions in a uniform manner. RESULTS The proposed framework was used to model a simple radiology report, which included temporal references. CONCLUSION Formal logic provides a framework for formalizing the representation of medical concepts. Actual implementations will be required to evaluate the practicality of this approach.

Terms used by nurses to describe patient problems: can SNOMED III represent nursing concepts in the patient record?

OBJECTIVE To analyze the terms used by nurses in a variety of data sources and to test the feasibility of using SNOMED III to represent nursing terms. DESIGN Prospective research design with manual matching of terms to the SNOMED III vocabulary. MEASUREMENTS The terms used by nurses to describe patient problems during 485 episodes of care for 201 patients hospitalized for Pneumocystis carinii pneumonia were identified. Problems from four data sources (nurse interview, intershift report, nursing care plan, and nurse progress note/flowsheet) were classified based on the substantive area of the problem and on the terminology used to describe the problem. A test subset of the 25 most frequently used terms from the two written data sources (nursing care plan and nurse progress note/flowsheet) were manually matched to SNOMED III terms to test the feasibility of using that existing vocabulary to represent nursing terms. RESULTS Nurses most frequently described patient problems as signs/symptoms in the verbal nurse interview and intershift report. In the written data sources, problems were recorded as North American Nursing Diagnosis Association (NANDA) terms and signs/symptoms with similar frequencies. Of the nursing terms in the test subset, 69% were represented using one or more SNOMED III terms.

Toward Terminology as Infrastructure

In the near future, high-level meetings at cancer care and research enterprises may be distracted by discussions of the terminology computers use to support collaborative interactions. Because the productivity of these enterprises will depend on comprehensive and timely terminology, discussions of terminology shortfalls may dominate management discussions until they are overcome and creating and maintaining quality terminology become part of the enterprise infrastructure. Because cancer research and care is necessarily broadly collaborative, this may happen to cancer enterprises before it happens to most other biomedical and healthcare enterprises.