The Concept File holds the clinical concepts that make up SNOMED CT. A concept is given meaning by its Fully Specified Name, which is held in the Description. A concept may be distinguished from or refined by association with other concepts using relationships, which are held in the Relationship.
Table 4.2.1-1: Concept file - Detailed Specification
|Part of Primary Key|
Uniquely identifies the concept.
Specifies the inclusive date at which the component version's state became the then current valid state of the component.
Note: In distribution files the effectiveTime should follow the short ISO date format (YYYYMMDD) and should not include the hours, minutes, seconds or timezone indicator.
Only one concept record with the same id field is current at any point in time. The current record will be the one with the most recent effectiveTime before or equal to the date under consideration. If the active field of this record is false ('0'), then the concept is inactive at that point in time.
Active descriptions that are still associated with the inactive concept will be added to the 900000000000490003 |Description inactivation indicator reference set|, with an associated value of 900000000000495008 |Concept non-current|