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Overview of the State Ambulatory Surgery and Services Databases (SASD)
The SASD are a set of longitudinal State-specific hospital ambulatory surgery databases included in the HCUP family. These databases are created by AHRQ through a Federal-State-Industry partnership.
State Ambulatory Surgery and Services Databases

The State Ambulatory Surgery and Services Databases (SASD) are part of the family of databases and software tools developed for the Healthcare Cost and Utilization Project (HCUP). The SASD include encounter-level data for ambulatory surgery and other outpatient services from hospital-owned facilities. In addition, some States provide ambulatory surgery and outpatient services from nonhospital-owned facilities. The SASD files include all patients, regardless of payer, providing a unique view of ambulatory surgeries and services in a defined market or in a State over time.

Developed through a Federal-State-Industry partnership sponsored by the Agency for Healthcare Research and Quality, HCUP data inform decisionmaking at the national, State, and community levels.

This page provides an overview of the SASD. For more details, see SASD Database Documentation and the Introduction to the SASD (PDF file, 196 KB; HTML).

The SASD capture surgeries performed on the same day in which patients are admitted and released in a given State. A number of States make their SASD files available for purchase through the HCUP Central Distributor.

Thirty-two States now participate in the SASD:

  • The SASD contain the ambulatory surgery encounter abstracts in participating States, translated into a uniform format to facilitate multi-State comparisons and analyses.
  • All of the databases include abstracts from hospital-affiliated ambulatory surgery sites. Some contain the universe of ambulatory surgery encounter abstracts for that State, including records from both hospital-affiliated and freestanding surgery centers. Composition and completeness of data files may vary from State to State.
  • The SASD contain a core set of clinical and nonclinical information on all patients, including individuals covered by Medicare, Medicaid, or private insurance, as well as those who are uninsured.
  • In addition to the core set of uniform data elements common to all SASD, some include other elements, such as the patient's race.
Free HCUP Tools & Software are also available to identify preventable hospitalizations, estimate costs, assess quality of care and patient safety, categorize diagnoses and procedures, and identify comorbidities.

Additional information on the SASD may be found in the Introduction to the SASD (PDF file, 196 KB; HTML).
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The SASD contain clinical and resource-use information that is included in a typical discharge abstract, with safeguards to protect the privacy of individual patients, physicians, and hospitals (as required by data sources). The SASD contain more than 100 clinical and nonclinical variables included in a hospital discharge abstract, such as:

  • All-listed diagnoses and procedures
  • Admission and discharge status
  • Patient demographic characteristics (e.g., sex, age, and, for some States, race)
  • Expected payment source
  • Total charges
  • Hospital identifiers that permit linkage to inpatient hospital databases, such as the AHRQ-sponsored State Inpatient Databases (SID) and the American Hospital Association Annual Survey File
Elements included in the SASD are not always available for all States, including the hospital county identifiers or HCUP's Revisit Variables. Please see the Availability of Data Elements by Year.
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The SASD are well suited for research that requires complete enumeration of hospital-based ambulatory surgery within market areas or States. Used with the SID, the SASD may be used to compare inpatient surgery data with ambulatory surgery data. The SASD promote comparative studies of health care services and support health care policy research on a variety of topics, including:

  • Analyses of same-day surgeries
  • Trends in outpatient surgery utilization, access, charges, insurance type, and outcomes
  • Shift in surgical procedures to outpatient facilities
  • Diffusion of medical technology
The SASD are used in a variety of publications:

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SASD releases for data years 1997 through 2011 are available for purchase through the HCUP Central Distributor. Costs vary by State and data year.

Prior to purchasing HCUP data, all individuals are required to take the online HCUP Data Use Agreement Training Course, and users of the SASD must read and sign the Data Use Agreement for State Databases (PDF file, 206 KB; HTML).

Instructions for purchasing the SASD are available in the State Ambulatory Surgery and Services Databases (SASD) Application Kit (PDF file, 529 KB).

Questions regarding purchasing databases can be directed to the HCUP Central Distributor:

Telephone: (866) 556-4287 (toll free)
Fax: (866) 792-5313 (toll free)

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The SASD data set comes in ASCII format and can be run on desktop computers with a DVD drive. To load and analyze the SASD, you will need the following:

  • A DVD drive
  • A hard drive with one to four gigabytes of space available, depending on the SID being used
  • SAS®, SPSS®, or similar analysis software
The data set comes with full documentation. SASD documentation and tools, including programs for loading the ASCII file into SAS or SPSS, are also available on the SASD Database Documentation page.

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Internet Citation: HCUP Databases. Healthcare Cost and Utilization Project (HCUP). June 2014. Agency for Healthcare Research and Quality, Rockville, MD.
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Last modified 6/27/14