CDM Documentation: Table Description and User Guide updates for the CONCEPT_ANCESTOR table section

[m-khitrun]

Hello,
Here I'd like to propose some updates for the Table Description and User Guide subsections of the CONCEPT_ANCESTOR table section:

Table Description
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 for Standard or Classification concepts. Using the CONCEPT_ANCESTOR table allows for querying for all descendants of a hierarchical concept, and the other way around. For example, drug ingredients and drug products, beneath them in the hierarchy, are all descendants of a drug class ancestor. This table is entirely derived from the CONCEPT, CONCEPT_RELATIONSHIP, and RELATIONSHIP tables.

User Guide
The CONCEPT_ANCESTOR table can be used to explore the hierarchical relationships captured in the table to gain insights into the hierarchical structure of clinical concepts. Understanding the hierarchical relationships of concepts can facilitate accurate interpretation and analysis of healthcare data. Also, by incorporating hierarchical relationships from the CONCEPT_ANCESTOR table, users can create cohorts containing related concepts within a hierarchical structure, enabling more comprehensive cohort definitions.

Best regards,
Masha