Attribute Definition
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 | FK Table | Description |
---|---|---|---|---|
attribute_definition_id | Yes | bigint | A unique identifier for each Attribute. | |
attribute_name | Yes | varchar(255) | A short description of the Attribute. | |
attribute_description | No | text | A complete description of the Attribute definition. | |
attribute_type_concept_id | Yes | bigint | CONCEPT | Type defining what kind of Attribute Definition the record represents and how the syntax may be executed. |
attribute_syntax | No | text | 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 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 theyear_of_birth
,month_of_birth
andday_of_birth
of the PERSON table. Thus, such an 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 thesubject_concept_id
in the COHORT_DEFINITION table.