SNOMED CT's problem list: ontologists' and logicians' therapy suggestions.

After a critical review of the present architecture of SNOMED CT, addressing both logical and ontological issues, we present a roadmap towards an overall improvement of this terminology. In particular, we recommend the following actions: Upper level categories should be rearranged according to a standard upper level ontology. Meta-class like concepts should be identified and removed from the taxonomy. SNOMED concepts denoting (non instantiable) individual entities (e.g. geographical regions) should be kept separate from those concepts that denote (instantiable) types. SNOMED binary relations should be reduced to a set of canonical ones, following existing recommendations. Taxonomies should be cleansed and split into disjoint partitions. The number of full definitions should be increased. Finally, we propose a new approach to modeling part-whole hierarchies, as well as the integration of qualifier relations into the description logic framework.