Procedure Occurrence

The PROCEDURE_OCCURRENCE table contains information about something being done to a patient.

The PROCEDURE_OCCURRENCE table contains records of activities or processes ordered by, or carried out by, a healthcare provider on the patient to have a diagnostic or therapeutic purpose. Procedures are present in various data sources in different forms with varying levels of standardization. For example:

• OPCS Procedure codes that are submitted as part of payment by results.
• Electronic Health Records that capture procedures as orders.
• Ventilation.
• Line insertion.
• Physiotherapy.

Field	Required	Type	FK Table	Description
procedure_occurrence_id	Yes	bigint		A system-generated unique identifier for each Procedure Occurrence.
person_id	Yes	bigint	PERSON	A foreign key identifier to the Person who is subjected to the Procedure. The demographic details of that Person are stored in the PERSON table.
procedure_concept_id	Yes	bigint	CONCEPT	A foreign key that refers to a standard procedure Concept identifier in the Standardized Vocabularies.
procedure_date	Yes	date		The date on which the Procedure was performed.
procedure_datetime	No	datetime		The date and time on which the Procedure was performed.
procedure_type_concept_id	Yes	bigint	CONCEPT	A foreign key to the predefined Concept identifier in the Standardized Vocabularies reflecting the type of source data from which the procedure record is derived.
modifier_concept_id	No	bigint	CONCEPT	A foreign key to a Standard Concept identifier for a modifier to the Procedure (e.g. bilateral).
quantity	No	integer		If the quantity value is omitted, a single procedure is assumed.
provider_id	No	bigint	PROVIDER	Not used.
visit_occurrence_id	No	bigint	VISIT_OCCURRENCE	A foreign key to the Visit Occurrence table during which the Procedure was carried out.
visit_detail_id	No	bigint	VISIT_DETAIL	A foreign key to the Visit Detail during which the Procedure was carried out.
procedure_source_value	No	varchar(50)		The source code for the Procedure as it appears in the source data. This code is mapped to a standard procedure Concept in the Standardized Vocabularies and the original code is stored here for reference. Procedure source codes are typically ICD-9-Proc, CPT-4, HCPCS or OPCS-4 codes.
procedure_source_concept_id	No	bigint	CONCEPT	A foreign key to a Procedure Concept that refers to the code used in the source.
modifier_source_value	No	varchar(50)		The source code for the qualifier as it appears in the source data.

Conventions

• Valid Procedure Concepts belong to the “Procedure” domain. Procedure Concepts are based on a variety of vocabularies: SNOMED-CT, ICD-9-Proc, CPT-4, HCPCS and OPCS-4, but also atypical Vocabularies such as ICD-9-CM or MedDRA.
• Initiation and cessation of invasive ventilation, tracheostomy, line insertion, physiotherapy, bronchoscopy, surgery, etc., are all recorded here.
• Procedures are expected to be carried out within one day and therefore have no end date.
• Procedures could involve the application of a drug, in which case the procedural component is recorded in the PROCEDURE_OCCURRENCE table and simultaneously the administered drug in the DRUG_EXPOSURE table, when both the procedural component and drug are identifiable.
• The Procedure Type defines from where the Procedure Occurrence is drawn or inferred. For administrative claims records the type indicates whether a Procedure was primary or secondary and their relative positioning within a claim.
• The Visit during which the procedure was performed is recorded through a reference to the VISIT_OCCURRENCE table.
• The Visit Detail during with the procedure was performed is recorded through a reference to the VISIT_DETAIL table.

Ventilation

• Specific elements of ventilation are recorded here. Importantly, this includes the following events:

  • Intubation
  • Extubation
  • Tracheostomy insertion
  • Decanulation (tracheostomy removal)

• If these events are not discretely recorded in the EHR, then they can be inferred and should be added as derived fields using a standardised approach, drawing on data from the OBSERVATION table (where all other data regarding ventilation can be found).