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This table changed in version 5.1 of the OMOP CDM. The field procedure_datetime was added.

The PROCEDURE_OCCURRENCE tabe 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:

  • Medical Claims include procedure codes that are submitted as part of a claim for health services rendered, including procedures performed.
  • Electronic Health Records that capture procedures as orders.
procedure_occurrence_idYesintegerA system-generated unique identifier for each Procedure Occurrence.
person_idYesintegerA 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_idYesintegerA foreign key that refers to a standard procedure Concept identifier in the Standardized Vocabularies.
procedure_dateYesdateThe date on which the Procedure was performed.
procedure_datetimeNodatetimeThe date and time on which the Procedure was performed.
procedure_type_concept_idYesintegerA 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_idNointegerA foreign key to a Standard Concept identifier for a modifier to the Procedure (e.g. bilateral)
quantityNointegerThe quantity of procedures ordered or administered.
provider_idNointegerA foreign key to the provider in the provider table who was responsible for carrying out the procedure.
visit_occurrence_idNointegerA foreign key to the visit in the visit table during which the Procedure was carried out.
procedure_source_valueNovarchar(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_idNointegerA foreign key to a Procedure Concept that refers to the code used in the source.
qualifier_source_valueNovarchar(50)The source code for the qualifier as it appears in the source data.


  • 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.
  • 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 table and simultaneously the administered drug in the drug exposure table when both the procedural component and drug are identifiable.
  • If the quantity value is omitted, a single procedure is assumed.
  • 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. This information is not always available.
  • The Provider carrying out the procedure is recorded through a reference to the PROVIDER table. This information is not always available.
documentation/cdm/procedure_occurrence.txt · Last modified: 2017/02/07 03:37 by cukarthik