Visit Occurrence

The VISIT_OCCURRENCE table contains the spans of time describing a Person’s individual episodes of care. They start with a presentation or admission (depending on their route) and end with the matched discharge.

Field	Required	Type	FK Table	Description
visit_occurrence_id	Yes	bigint		A unique identifier for each Person’s visit or encounter at a healthcare provider.
person_id	Yes	bigint	PERSON	A foreign key identifier to the Person for whom the visit is recorded.
visit_concept_id	Yes	bigint	CONCEPT	A foreign key that refers to a visit Concept identifier in the Standardized Vocabularies.
visit_start_date	Yes	date		The UTC start date of the visit.
visit_start_datetime	No	datetime		The UTC date and time of the admission.
visit_end_date	No	date		The UTC end date of the visit. NULL means the patient has not been discharged.
visit_end_datetime	No	datetime		The UTC date and time of the visit end. NULL means the patient has not been discharged.
visit_type_concept_id	No	bigint	CONCEPT	Not used.
provider_id	No	bigint	PROVIDER	Not used.
care_site_id	Yes	bigint	CARE_SITE	The trust or hospital the admission was at.
visit_source_value	No	varchar(50)		Visit / episode / contact identifier in the local site system.
visit_source_concept_id	No	bigint	CONCEPT	Not used.
admitting_source_value	No	varchar(50)		Raw EHR value for admitting source.
admitting_source_concept_id	No	bigint	CONCEPT	A foreign key to the predefined concept in the Place of Service Vocabulary reflecting the admitting source for a visit. Same possible values as discharge_to_concept_id .
discharge_to_source_value	No	varchar(50)		Raw EHR value for discharge to.
discharge_to_concept_id	No	bigint	CONCEPT	A foreign key to the predefined concept in the Place of Service Vocabulary reflecting the discharge disposition for a visit.
preceding_visit_occurrence_id	No	bigint	VISIT_OCCURRENCE	A foreign key to the Visit Occurrence record of the visit immediately preceding this visit.
last_updated_datetime	Yes	datetime		Initially this is the time the row was written to OMOP. If the row is subsequently updated, it then becomes the most recent update time.
deleted_datetime	No	datetime		NULL initially. Set to the time when the row was marked for deletion. A value in this column sent to the central data source will result in this row being deleted from the combined dataset. Deletions only need to be sent once.

Conventions

• A Visit Occurrence is recorded for each visit to a healthcare facility.
• Valid Visit Concepts belong to the “Visit” domain.
• At any one day, there could be more than one visit.
• preceding_visit_occurrence_id can be used to link a visit immediately preceding the current visit.
• A transfer between two hospitals within the same trust should create a new Visit Occurrence where possible.

Relationship to VISIT_DETAIL