General SASD Notes

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

The California Office of Statewide Health Planning and Development (OSHPD) collects data on ambulatory surgery encounters from general acute care hospitals and other licensed facilities. OSHPD defines ambulatory surgery procedures as those performed on an outpatient basis in general operating rooms, ambulatory surgery rooms, endoscopy units, or cardiac catheterization laboratories. If a procedure was performed elsewhere (such as in a radiology unit), OSHPD does not require an ambulatory surgery record to be filed.

Outpatient Data File Provided to HCUP by the Partner

OSHPD provides HCUP with their complete ambulatory surgery file that is separated from their emergency department (ED) file. OSHPD uses a patient type indicator to distinguish between patients treated in an ED (record type value "E") and patients with an ambulatory surgery (record type value "A").

OSHPD excluded AS encounters that, after processing by OSHPD, did not contain a complete and "in-range" admission date or discharge date. California also excluded AS encounters that had an unknown or missing date of birth.

OSHPD removes ICD-9-CM and ICD-10-CM diagnoses codes for HIV test results.

Beginning with 2009 data, OSHPD changed regulations to require hospitals to report all external cause of injury diagnosis codes including those specific to medical misadventures. Prior to 2009, OSHPD did not require collection of diagnosis codes identifying medical misadventures.

Selection of Records for Inclusion in the SASD

All records identified by California as ambulatory surgery (AS) (i.e., included in the separate AS data file provided to HCUP) are included in the SASD (HCUP data element STATE_AS=1 based on record type "A").

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

All hospital-owned facilities that perform ambulatory surgeries are required by law to report to OSHPD. Nonhospital-owned facilities that are licensed by the California Department of Public Health are also required by law to report data to OSHPD if at least one ambulatory surgery procedure is performed.

Beginning in 2008, there was a large decline in the number of nonhospital-owned facilities reporting to OSHPD. The decrease has to do with a licensing issue that arose in California as a result of the Capen v. Shewry decision in 2007. This ruling exempted doctor-owned ambulatory surgery clinics from the need to obtain a facility license from the California Department of Health. Because the OSHPD reporting requirement is tied to licensure, the doctor-owned facilities stopped reporting their data.

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 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.


Internet Citation: HCUP Central Distributor SID California File Composition. Healthcare Cost and Utilization Project (HCUP). July 2010. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/db/state/sasddist/sasddist_filecompca.jsp.
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Last modified 7/19/10