2.1 KiB
2.1 KiB
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 | varchar(MAX) | 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 | varchar(MAX) | 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_initiation_date | No | Date | A date to indicate when the Cohort was initiated in the COHORT table |
Conventions
- The cohort_definition_syntax does not prescribe any specific syntax or programming language. Typically, it would be any flavor SQL, a cohort definition language, or a free-text description of the algorithm.
- The subject_concept_id determines what the individual subjects or entities of the Cohort consists of. In most cases, that would be a Person (patient). But cohorts could also be constructed for Providers, Visits or any other Domain. Note that the Domain is not codified using the alphanumerical domain_id like in the CONCEPT table. Instead, the corresponding Concept is used. The Concepts for each domain can be obtained from the DOMAIN table in the domain_concept_id.