Implementing description-logic rules for SNOMED-CT attributes through a table-driven approach

Maintaining a large controlled biomedical vocabulary requires ensuring the content's internal consistency. This is done through rules, specified by the vocabulary's curators, which denote how the vocabulary's concepts should be defined. When individual organizations deploy such vocabularies, local concepts are typically added and linked to concepts in the main vocabulary: the process of maintaining and linking local content should follow the same rules. The operation of content-maintenance software can be facilitated by maintaining such rules in computable form. In this paper, we demonstrate how to implement computable rules for attribute usage in SNOMED CT using a table-driven approach where a given rule is expressed as one or more rows in a table and is consulted by generic code. This approach, which is tailored to database implementations, is computationally efficient and allows new attribute-definition rules to be created as data while needing minimal or no code modification.