Types of Ambulatory Surgery and Other Outpatient Services Collected by the Partner

The Hospital Industry Data Institute (HIDI), owned by the Missouri Hospital Association, collects data on ambulatory surgery and other outpatient services such as observation services and emergency department visits. HIDI uses the following hierarchy to identify each outpatient record with a place of service:

• Emergency department (value 1)
• Outpatient surgery (value 2)
• Observation care (value 3)
• Other outpatient (value 4).

Through September 30, 2015, the hospitals defined how they assign the place of service. HIDI edits the reported place of service code, and they expect a reported procedure code in the invasive range for records with an outpatient place of service for outpatient surgery. Invasive procedure codes include Current Procedural Terminology (CPT®) codes 10000-69999 and International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes 01.0-86.99, inclusive. A new definition for place of service as of October 1 ,2015 with the transition to ICD-10-CM/PCS is not available.

Because of the hierarchical assignment for the place of service flag, an outpatient encounter that involves outpatient surgery and observation services is only flagged as ambulatory surgery. However, ambulatory surgery records with evidence of observation services can be identified by HCUP data element HCUP_OS.

Outpatient Data File Provided to HCUP by the Partner

Beginning in data year 2017, HIDI provides their complete outpatient file to HCUP, with the type of outpatient record identified by a place of service. The place of service is stored in the HCUP data element OPservice.

From data year 2012-2016, HIDI provided a subset of their outpatient file to HCUP, which was based on a pre-defined list of the following ICD-9-CM (through September 30, 2015) and CPT procedure codes for ambulatory surgery (AS):

Table 1. Range of ICD-9-CM Procedure Codes to be Used when Selecting AS Records

Table 2. Range of CPT-4 Procedure Codes to be Used when Selecting AS Records

Prior to data year 2012, HIDI provided only the outpatient surgery and emergency department records from their broader outpatient data set to HCUP.

Selection of Records for Inclusion in the SASD

All records identified by HIDI as ambulatory surgery are included in the SASD (STATE_AS=1 based on place of service 2). Any other nonemergent outpatient records (STATE_ED not equal to 1) also are included.

Additionally, any records in the SASD that also have evidence of emergency department services based on the HCUP criteria (HCUP data element HCUP_ED > 0), are also included in the HCUP State Emergency Department Databases (SEDD). These records will have the same value for the HCUP data element KEY.

Types of Facilities Included in the Files Provided to HCUP by the Partner

HIDI collects outpatient data from hospital-based facilities. HIDI collects data from some but not all of the nonhospital-based facilities, but they do not provide these data to HCUP.

Identification of Hospital-Owned Ambulatory Surgery and Other Types of Outpatient Facilities in the SASD

The designation of a facility as hospital-owned is specific to its financial relationship with a hospital that provides inpatient care and not related to its physical location. Hospital-owned ambulatory surgery and other outpatient care facilities may be contained within the hospital, physically attached to the hospital, or located in a different geographic area. The designation as hospital-owned means that HCUP can identify that the hospital is billing for this service.

Starting in data year 2018, the HCUP data element HOSPITAL_OWNED can be used to identify hospital-owned facilities with ambulatory surgery and possibly other outpatient care data in the SASD. A facility is considered hospital-owned (HOSPITAL_OWNED = 1) if any one of the following is true:

• The facility is listed in the American Hospital Association (AHA) Annual Survey Database^TM.
• The facility is not listed in the AHA database, but the facility provides inpatient discharge data to HCUP.
• Documentation provided by the data source clearly indicates that the facility is hospital-owned.

If the facility in the SASD does not meet any of the above criteria, it is marked as not being owned by a hospital (HOSPITAL_OWNED = 0). Not all hospitals report to the AHA, so there is a possibility that some facilities marked with HOSPITAL_OWNED=0 are hospital-owned.

From data year 1998-2018, the HCUP data element was called FREESTANDING. A facility is considered hospital-owned (FREESTANDING = 0) if any one of the following is true:

• The facility is listed in the American Hospital Association (AHA) Annual Survey Database^TM.
• The facility is not listed in the AHA database, but the facility provides inpatient discharge data to HCUP.
• Documentation provided by the data source clearly indicates that the facility is hospital-owned.

If the facility in the SASD does not meet any of the above criteria, it is marked as not being owned by a hospital (FREESTANDING = 1). Not all hospitals report to the AHA, so there is a possibility that some facilities marked with FREESTANDING=1 are hospital-owned.

Exclusion of Records During HCUP Data Processing

Beginning with 2016 data, records with a discharge disposition of "still a patient" are retained in the HCUP SASD. Prior to 2016 data, these records were excluded.

Beginning in 2010, records with a designation of "admitted as an inpatient" are retained in the SASD, even though this rarely occurs. Prior to 2010, records with a designation of "admitted as an inpatient" were excluded from the files.