In general, it is very straightforward to store concept identifiers in electronic medical records and represent them in messages. Information models typically specify the fields that can contain coded entries. For each of these fields there may be additional constraints governing exactly which concept identifiers are applicable. However, because modern terminologies such as SNOMED CT are compositional, allowing concept expressions to be pre-coordinated within the terminology or post-coordinated within the medical record, there remains the potential to express a concept in more than one way. Often times, the various representations are similar, but not equivalent. This paper describes an approach for retrieving these pre- and post-coordinated concept expressions: (1) Create concept expressions using a logically-well-structured terminology (e.g., SNOMED CT) according to the rules of a well-specified information model (in this paper we use the HL7 RIM); (2) Transform pre- and post-coordinated concept expressions into a normalized form; (3) Transform queries into the same normalized form. The normalized instances can then be directly compared to the query. Several implementation considerations have been identified. Transformations into a normal form and execution of queries that require traversal of hierarchies need to be optimized. A detailed understanding of the information model and the terminology model are prerequisites. Queries based on the semantic properties of concepts are only as complete as the semantic information contained in the terminology model. Despite these considerations, the approach appears powerful and will continue to be refined.
[1]
Philip J. B. Brown,et al.
Evaluation of the quality of information retrieval of clinical findings from a computerized patient database using a semantic terminological model.
,
2000,
Journal of the American Medical Informatics Association : JAMIA.
[2]
Kent A. Spackman,et al.
Normal forms for description logic expressions of clinical concepts in SNOMED RT
,
2001,
AMIA.
[3]
G W Beeler,et al.
HL7 version 3--an object-oriented methodology for collaborative standards development.
,
1998,
International journal of medical informatics.
[4]
Mark A. Musen,et al.
Research Paper: A Logical Foundation for Representation of Clinical Data
,
1994,
J. Am. Medical Informatics Assoc..