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documentation:cdm:concept_ancestor

CONCEPT_ANCESTOR table

The CONCEPT_ANCESTOR table is designed to simplify observational analysis by providing the complete hierarchical relationships between Concepts. Only direct parent-child relationships between Concepts are stored in the CONCEPT_RELATIONSHIP table. To determine higher level ancestry connections, all individual direct relationships would have to be navigated at analysis time. The CONCEPT_ANCESTOR table includes records for all parent-child relationships, as well as grandparent-grandchild relationships and those of any other level of lineage. Using the CONCEPT_ANCESTOR table allows for querying for all descendants of a hierarchical concept. For example, drug ingredients and drug products are all descendants of a drug class ancestor.

This table is entirely derived from the CONCEPT, CONCEPT_RELATIONSHIP and RELATIONSHIP tables.

FieldRequiredTypeDescription
ancestor_concept_idYesintegerA foreign key to the concept in the concept table for the higher-level concept that forms the ancestor in the relationship.
descendant_concept_idYesintegerA foreign key to the concept in the concept table for the lower-level concept that forms the descendant in the relationship.
min_levels_of_separationYesintegerThe minimum separation in number of levels of hierarchy between ancestor and descendant concepts. This is an attribute that is used to simplify hierarchic analysis.
max_levels_of_separationYesintegerThe maximum separation in number of levels of hierarchy between ancestor and descendant concepts. This is an attribute that is used to simplify hierarchic analysis.

Conventions

  • Each concept is also recorded as an ancestor of itself.
  • Only valid and Standard Concepts participate in the CONCEPT_ANCESTOR table. It is not possible to find ancestors or descendants of deprecated or Source Concepts.
  • Usually, only Concepts of the same Domain are connected through records of the CONCEPT_ANCESTOR table, but there might be exceptions.
documentation/cdm/concept_ancestor.txt · Last modified: 2014/12/06 17:32 by cgreich