THIS IS OUTDATED. All documentation is now on the github wiki. Please refer there or to the CDM working group for more information
The COHORT_DEFINITION table contains records defining a Cohort derived from the data through the associated description and syntax and upon instantiation (execution of the algorithm) placed into the COHORT table. Cohorts are a set of subjects that satisfy a given combination of inclusion criteria for a duration of time. The COHORT_DEFINITION table provides a standardized structure for maintaining the rules governing the inclusion of a subject into a cohort, and can store operational programming code to instantiate the cohort within the OMOP Common Data Model.
| Field | Required | Type | Description |
|---|---|---|---|
| cohort_definition_id | Yes | integer | A unique identifier for each Cohort. |
| cohort_definition_name | Yes | varchar(255) | A short description of the Cohort. |
| cohort_definition_description | No | CLOB | A complete description of the Cohort definition |
| definition_type_concept_id | Yes | integer | Type defining what kind of Cohort Definition the record represents and how the syntax may be executed |
| cohort_definition_syntax | No | CLOB | Syntax or code to operationalize the Cohort definition |
| subject_concept_id | Yes | integer | A foreign key to the Concept to which defines the domain of subjects that are members of the cohort (e.g., Person, Provider, Visit). |
| cohort_instantiation_date | No | Date | A date to indicate when the Cohort was instantiated in the COHORT table |