General SASD Notes

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

The Center for Health Information Analysis (CHIA) at the University of Nevada at Las Vegas, under the authority of the Nevada Department of Health and Human Services, collects data on ambulatory surgery and other outpatient services such as observation services, radiology, and emergency department visits. CHIA defines ambulatory surgery as having a revenue center code of 036x and a discharge disposition code of home (value 01) or home health care (value 06).

CHIA uses the following hierarchy to identify each outpatient record with a place of service:

  • Emergency department (value ED)
  • Outpatient surgery (value OS)
  • Ambulatory surgery center (value AS)
  • Other outpatient (value TH).

CHIA defines an ambulatory surgical center (ASC) as any distinct entity that operates exclusively for the purpose of providing surgical services to patients who do not require hospitalization. In general, ASCs are medical facilities that specialize in elective same day or outpatient surgical procedures. They do not offer emergency care. Patients treated at ASCs do not require admission to a hospital and are well enough to return home following a procedure.

Because of the hierarchical assignment for the place of service, an outpatient encounter that involves emergency department services and outpatient surgery is only flagged as emergency department.

Outpatient Data File Provided to HCUP by the Partner

CHIA provides their complete outpatient file to HCUP. The place of service of outpatient surgery and ambulatory surgery center are used to set the HCUP data element STATE_AS. The patient type of emergency department visit is used to set the HCUP data element STATE_ED.

Selection of Records for Inclusion in the SASD

All records identified by CHIA as ambulatory surgery are included in the SASD (STATE_AS = 1 based on place of service OS, AS, or TH). Any other nonemergent, outpatient records (STATE_ED not equal 1) also are included in the SASD.

Additionally, any record in the SASD that also have evidence of ED 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

A state license is required by the Nevada Health Department before any health care facility may begin providing outpatient services. CHIA collects outpatient data from all licensed Nevada hospitals and nonhospital-owned ambulatory surgery centers.

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 DatabaseTM.
  • 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 DatabaseTM.
  • 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 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.


Internet Citation: HCUP Central Distributor SASD Nevada File Composition. Healthcare Cost and Utilization Project (HCUP). September 2013. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/db/state/sasddist/sasddist_filecompnv.jsp.
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Last modified 9/5/13