title: Structural measures to track the evolution of SNOMED CT hierarchies.
abstract: The Systematized Nomenclature of Medicine Clinical Terms (SNOMED CT) is an extensive reference terminology with an attendant amount of complexity. It has been updated continuously and revisions have been released semi-annually to meet users' needs and to reflect the results of quality assurance (QA) activities. Two measures based on structural features are proposed to track the effects of both natural terminology growth and QA activities based on aspects of the complexity of SNOMED CT. These two measures, called the structural density measure and accumulated structural measure, are derived based on two abstraction networks, the area taxonomy and the partial-area taxonomy. The measures derive from attribute relationship distributions and various concept groupings that are associated with the abstraction networks. They are used to track the trends in the complexity of structures as SNOMED CT changes over time. The measures were calculated for consecutive releases of five SNOMED CT hierarchies, including the Specimen hierarchy. The structural density measure shows that natural growth tends to move a hierarchy's structure toward a more complex state, whereas the accumulated structural measure shows that QA processes tend to move a hierarchy's structure toward a less complex state. It is also observed that both the structural density and accumulated structural measures are useful tools to track the evolution of an entire SNOMED CT hierarchy and reveal internal concept migration within it.
authors.affiliation: Computer Science and Information Systems-BUSN, Stockton University, Galloway, NJ 08205, United States. Electronic address: duo.wei@stockton.edu.
authors.forename: Duo
authors.initials: D
authors.lastname: Wei
authors.affiliation: Computer Science Dept., New York Institute of Technology, New York, NY 10023, United States.
authors.forename: Huanying
authors.initials: H
authors.lastname: Helen Gu
authors.affiliation: Computer Science Dept., New Jersey Institute of Technology, Newark, NJ 07102, United States.
authors.forename: Yehoshua
authors.initials: Y
authors.lastname: Perl
authors.affiliation: Information Technology Dept., New Jersey Institute of Technology, Newark, NJ 07102, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Halper
authors.affiliation: Computer Science Dept., New Jersey Institute of Technology, Newark, NJ 07102, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Ochs
authors.affiliation: Computer Science Dept., New Jersey Institute of Technology, Newark, NJ 07102, United States; Halfpenny Technologies Inc., Blue Bell, PA 19422, United States.
authors.forename: Gai
authors.initials: G
authors.lastname: Elhanan
authors.affiliation: Computer Information Systems Dept., BMCC, CUNY, New York, NY 10007, United States.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000068598:Data Accuracy; D039061:Systematized Nomenclature of Medicine
keywords: Abstraction network; Complexity measure; Quality assurance; SNOMED CT; Terminology