General SASD Notes

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

Starting in October 2015, the Michigan Health & Hospital Association (MHA) collects information on ambulatory surgeries and other outpatient services identified by Current Procedural Terminology (CPTŪ) procedure codes listed in the Medicine and Surgery chapters of the CPT manual. Prior to October 2015, MHA collects information on ambulatory surgeries defined by a principal or secondary International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure code in the range of 00.50 through 86.99 (excluding 17.70) and 98.51. If a hospital collects CPT procedure codes instead of ICD-9-CM codes, then CPT codes equivalent to the ICD-9-CM range specified above are accepted. Information about these procedures is collected regardless of where in the outpatient setting the procedure was performed (e.g., ambulatory surgery suite, emergency department). In addition, the MHA ambulatory surgery data includes information on patients who have outpatient observation stays, as long the ambulatory surgery criteria described above are met.

Outpatient Data File Provided to HCUP by the Partner

MHA provides HCUP with their complete ambulatory surgery file. The type of service is identified as outpatient without observation (value 30), outpatient with observation (value 31), and outpatient birth (value 32). The record type is stored in the HCUP data element OPservice.

Selection of Records for Inclusion in the SASD

All records identified as ambulatory surgery by MHA (i.e., included in the separate AS data file provided to HCUP) are included in the SASD (STATE_AS=1 based on record type values 30 and 32). Records with record type = 31, for outpatient with observation, are used to set the State-defined observation service flag (STATE_OS).

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

MHA collects data on ambulatory surgeries performed in hospital-owned facilities. MHA does not collect data on ambulatory surgeries performed in nonhospital-owned facilities.

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

For data year 2018, there were 3 milliion largely blank records (no CPT codes, diagnosis codes, or total charges) that were dropped from the file.

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 Michigan File Composition. Healthcare Cost and Utilization Project (HCUP). August 2006. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/db/state/sasddist/sasddist_filecompmi.jsp.
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Last modified 8/15/06