Differences

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--- documentation:cdm:concept_ancestor [2014/12/06 17:32] – cgreich
+++ documentation:cdm:concept_ancestor [2017/10/02 21:29] (current) – aostropolets
@@ Line 1: / Line 1: @@
 ===== CONCEPT_ANCESTOR table =====
+**THIS IS OUTDATED. All documentation is now on the [[https://github.com/OHDSI/CommonDataModel/wiki|github wiki]]. Please refer there or to the [[projects:workgroups:cdm-wg|CDM working group]] for more information**
 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.
@@ Line 10: / Line 11: @@
 |min_levels_of_separation|Yes|integer|The 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_separation|Yes|integer|The maximum separation in number of levels of hierarchy between ancestor and descendant concepts. This is an attribute that is used to simplify hierarchic analysis.|
+A path between two concepts can be characterized by the sequence of relationships that need to be traversed in order to reach a descendant concept from an ancestor concept.
+For example, for concepts
+^descendant_concept_id^descendant_concept_name^ancestor_concept_id^ancestor_concept_name^min_levels_of_separation^max_levels_of_separation^
+|313217|Atrial fibrillation|321588|Heart disease|3|4|
+the shortest path in concept_relationship will be :
+Atrial fibrillation **Is a** 4226399 Fibrillation **Is a**
+44784217 Cardiac arrhythmia **Is a** 321588  Heart disease
+the longest:
+Atrial fibrillation **Is a** 4068155  Atrial arrhythmia **Is a**
+4248028  Supraventricular arrhythmia **Is a** 44784217 Cardiac arrhythmia **Is a**
+  Heart disease
+{{:documentation:cdm:concept_ancestor.png?200|}}
 ==== Conventions ====
@@ Line 16: / Line 38: @@
   * 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.