Benefits of an Object-oriented Database Representation for Controlled Medical Terminologies

Abstract

A b s t r a c t Objective:Controlled medical terminologies (CMTs) have been recognized as important tools in a variety of medical informatics applications, ranging from patient-record systems to decision-support systems. Controlled medical terminologies are typically organized in semantic network structures consisting of tens to hundreds of thousands of concepts. This overwhelming size and complexity can be a serious barrier to their maintenance and widespread utilization. The authors propose the use of object-oriented databases to address the problems posed by the extensive scope and high complexity of most CMTs for maintenance personnel and general users alike. Design:The authors present a methodology that allows an existing CMT, modeled as a semantic network, to be represented as an equivalent object-oriented database. Such a representation is called an object-oriented health care terminology repository (OOHTR). Results:The major benefit of an OOHTR is its schema, which provides an important layer of structural abstraction. Using the high-level view of a CMT afforded by the schema, one can gain insight into the CMT's overarching organization and begin to better comprehend it. The authors' methodology is applied to the Medical Entities Dictionary (MED), a large CMT developed at Columbia-Presbyterian Medical Center. Examples of how the OOHTR schema facilitated updating, correcting, and improving the design of the MED are presented. Conclusion:The OOHTR schema can serve as an important abstraction mechanism for enhancing comprehension of a large CMT, and thus promotes its usability.

Abstraction networks for terminologies: Supporting management of “big knowledge”

“…Fundamentally, an abstraction network serves to capture the essence of an underlying terminology while ignoring its minutiae. In this capacity, for example, the object-oriented schema helped to expose and repair some errors and inconsistencies in the MED [37,38]. As a matter of fact, the excerpt of the MED abstraction network in Figure 4 is the one obtained after resolving various errors and inconsistencies that were exposed with a prior version of the abstraction network derived from the MED’s 1996 release.…”

“…In [37, 38], we presented an abstraction network in the form of an object-oriented database schema for the Medical Entities Dictionary (MED) [15,16] and related offshoots, e.g., the InterMed [39]. In this context, the nodes are object classes and the child-of relationships are in the form of “subclass” links between classes.…”

“…In other words, a root functions as a top-level concept within its node and is, in fact, used as the name of the node. (For the handling of multiple roots within a node, see [37, 38]. ) A child-of is defined from node A to node B if there exists an IS-A relationship from the root of A to a concept in B .…”

“…For the 1996 version of the MED, consisting of about 43,000 concepts, the abstraction network contains 90 nodes [37, 38]. Its abstraction ratio is thus 478:1.…”

Enhancing OODB semantics to support browsing in an OODB vocabulary representation

“…The database schema of an OOVR, called the OOVR schema, gives users an abstract view of the vocabulary, compared to the tens of thousands of concepts in the vocabulary itself ‡ . An OOVR schema can be utilized by different types of vocabulary users [19]. For instance, casual users can use it to browse the contents of the vocabulary.…”