COMMENTONTABLEconceptIS'A list of all valid terminology concepts across domains and their attributes. Concepts are derived from existing standards.';
COMMENTONCOLUMNconcept.concept_idIS'A system-generated identifier to uniquely identify each concept across all concept types.';
COMMENTONCOLUMNconcept.concept_nameIS'An unambiguous, meaningful and descriptive name for the concept.';
COMMENTONCOLUMNconcept.concept_levelIS'The level of hierarchy associated with the concept. Different concept levels are assigned to concepts to depict their seniority in a clearly defined hierarchy, such as drugs, conditions, etc. A concept level of 0 is assigned to concepts that are not part of a standard vocabulary, but are part of the vocabulary for reference purposes (e.g. drug form).';
COMMENTONCOLUMNconcept.concept_classIS'The category or class of the concept along both the hierarchical tree as well as different domains within a vocabulary. Examples are ''Clinical Drug'', ''Ingredient'', ''Clinical Finding'' etc.';
COMMENTONCOLUMNconcept.vocabulary_idIS'A foreign key to the vocabulary table indicating from which source the concept has been adapted.';
COMMENTONCOLUMNconcept.concept_codeIS'The concept code represents the identifier of the concept in the source data it originates from, such as SNOMED-CT concept IDs, RxNorm RXCUIs etc. Note that concept codes are not unique across vocabularies.';
COMMENTONCOLUMNconcept.valid_start_dateIS'The date when the was first recorded.';
COMMENTONCOLUMNconcept.valid_end_dateIS'The date when the concept became invalid because it was deleted or superseded (updated) by a new concept. The default value is 31-Dec-2099.';
COMMENTONCOLUMNconcept.invalid_reasonIS'Concepts that are replaced with a new concept are designated "Updated" (U) and concepts that are removed without replacement are "Deprecated" (D).';
COMMENTONTABLErelationshipIS'A list of relationship between concepts. Some of these relationships are generic (e.g. "Subsumes" relationship), others are domain-specific.';
COMMENTONCOLUMNrelationship.relationship_idIS'The type of relationship captured by the relationship record.';
COMMENTONCOLUMNrelationship.relationship_nameIS'The text that describes the relationship type.';
COMMENTONCOLUMNrelationship.is_hierarchicalIS'Defines whether a relationship defines concepts into classes or hierarchies. Values are Y for hierarchical relationship or NULL if not';
COMMENTONCOLUMNrelationship.defines_ancestryIS'Defines whether a hierarchical relationship contributes to the concept_ancestor table. These are subsets of the hierarchical relationships. Valid values are Y or NULL.';
COMMENTONCOLUMNrelationship.reverse_relationshipIS'relationship ID of the reverse relationship to this one. Corresponding records of reverse relationships have their concept_id_1 and concept_id_2 swapped.';
COMMENTONTABLEconcept_relationshipIS'A list of relationship between concepts. Some of these relationships are generic (e.g. ''Subsumes'' relationship), others are domain-specific.';
COMMENTONCOLUMNconcept_relationship.concept_id_1IS'A foreign key to the concept in the concept table associated with the relationship. relationships are directional, and this field represents the source concept designation.';
COMMENTONCOLUMNconcept_relationship.concept_id_2IS'A foreign key to the concept in the concept table associated with the relationship. relationships are directional, and this field represents the destination concept designation.';
COMMENTONCOLUMNconcept_relationship.relationship_idIS'The type of relationship as defined in the relationship table.';
COMMENTONCOLUMNconcept_relationship.valid_start_dateIS'The date when the the relationship was first recorded.';
COMMENTONCOLUMNconcept_relationship.valid_end_dateIS'The date when the relationship became invalid because it was deleted or superseded (updated) by a new relationship. Default value is 31-Dec-2099.';
COMMENTONCOLUMNconcept_relationship.invalid_reasonIS'Reason the relationship was invalidated. Possible values are D (deleted), U (replaced with an update) or NULL when valid_end_date has the default value.';
COMMENTONTABLEconcept_ancestorIS'A specialized table containing only hierarchical relationship between concepts that may span several generations.';
COMMENTONCOLUMNconcept_ancestor.ancestor_concept_idIS'A foreign key to the concept code in the concept table for the higher-level concept that forms the ancestor in the relationship.';
COMMENTONCOLUMNconcept_ancestor.descendant_concept_idIS'A foreign key to the concept code in the concept table for the lower-level concept that forms the descendant in the relationship.';
COMMENTONCOLUMNconcept_ancestor.max_levels_of_separationIS'The maximum separation in number of levels of hierarchy between ancestor and descendant concepts. This is an optional attribute that is used to simplify hierarchic analysis. ';
COMMENTONCOLUMNconcept_ancestor.min_levels_of_separationIS'The minimum separation in number of levels of hierarchy between ancestor and descendant concepts. This is an optional attribute that is used to simplify hierarchic analysis.';