documentation:cdm:attribute

ATTRIBUTE_DEFINITION table

THIS IS OUTDATED. All documentation is now on the github wiki. Please refer there or to the CDM working group for more information

The ATTRIBUTE_DEFINITION table contains records defining Attributes, or covariates, to members of a Cohort through an associated description and syntax and upon instantiation (execution of the algorithm) placed into the COHORT_ATTRIBUTE table. Attributes are derived elements that can be selected or calculated for a subject in a Cohort. The ATTRIBUTE_DEFINITION table provides a standardized structure for maintaining the rules governing the calculation of covariates for a subject in a Cohort, and can store operational programming code to instantiate the Attributes for a given Cohort within the OMOP Common Data Model.

Field	Required	Type	Description
attribute_definition_id	Yes	integer	A unique identifier for each Attribute.
attribute_name	Yes	varchar(255)	A short description of the Attribute.
attribute_description	No	CLOB	A complete description of the Attribute definition
attribute_type_concept_id	Yes	integer	Type defining what kind of Attribute Definition the record represents and how the syntax may be executed
attribute_syntax	No	CLOB	Syntax or code to operationalize the Attribute definition

Conventions

Like the definition syntax field for the COHORT_DEFINITION table, the attribute_definition_syntax does not prescribe any specific syntax or programming language. Typically, it would be any flavor SQL, or a cohort definition language, or a free-text description of the algorithm.
The Attribute Definition is generic and not necessarily related to a specific Cohort Definition, however the instantiated Attribute is linked to the Cohort records (see below the COHORT table. For example, the Attribute “Age” can be defined as the amount of time between the cohort_start_date of the COHORT table and the year_of_birth, month_of_birth and day_of_birth of the PERSON table. Thus, such a Attribute Definition can be applied and instantiated with any Cohort, as long as it is applied to a Cohort of the same Domain (Person in this case), as it is defined in the subject_concept_id in the COHORT_DEFINITION table.