The State Inpatient Databases (SID) are one in a family of databases and software tools developed as part of the Healthcare Cost and Utilization Project (HCUP). A Federal-State-Industry partnership sponsored by the Agency for Healthcare Research and Quality, HCUP data inform decision making at the national, State, and community levels. This page provides an overview of the SID. For more details, see Overview of the SID (PDF file, 133 KB).

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Contents:

• What Are the SID?
• What Data Elements Are in the SID?
• What States Make Up the SID?
• How Are the SID Used?
• Hardware and Software Requirements
• How Can Users Obtain SID Data?
• Need Help?

The State Inpatient Databases (SID) are a powerful set of hospital databases from data organizations in 36 participating States.

• The SID contain the universe of the inpatient discharge abstracts in participating States, translated into a uniform format to facilitate multi-State comparisons and analyses.
• Together, the SID encompass about 90 percent of all U.S. community hospital discharges. Some States include discharges from specialty facilities, such as acute psychiatric hospitals.
• The SID contain a core set of clinical and nonclinical information on all patients, regardless of payer, including persons covered by Medicare, Medicaid, private insurance, and the uninsured.
• In addition to the core set of uniform data elements common to all SID, some include other elements, such as the patient's race.

The SID contains clinical and resource use information included in a typical discharge abstract, with safeguards to protect the privacy of individual patients, physicians, and hospitals (as required by data sources).

The SID excludes data elements that could directly or indirectly identify individuals. Purchase of the files is open to all users who sign a Data Use Agreement (PDF file, 47 KB). Users must agree to use the database for research and statistical purposes only and to make no attempts to identify individuals.

Identities of institutions are available only in States where data sources already make that information public or agree to its release. For these institutions and for research purposes only, linkage is possible to data from the Annual Survey of the American Hospital Association.

Select for the Overview of the SID (PDF file, 133 KB).

Researchers and policymakers use SID to investigate questions unique to one State; to compare data from two or more States; to conduct market area research or small area variation analyses; and to identify State-specific trends in inpatient care utilization, access, charges, and outcomes.

The SID contain more than 100 clinical and nonclinical variables included in a hospital discharge abstract, such as:

• Principal and secondary diagnoses
• Principal and secondary procedures
• Admission and discharge status
• Patient demographics (e.g., gender, age, and, for some States, race)
• Expected payment source (e.g., Medicare, Medicaid, private insurance, self-pay; for some States, additional discrete payer categories, such as managed care)
• Total charges
• Length of stay
• For some States, hospital and county identifiers that permit linkage to the American Hospital Association Annual Survey File and the Area Resource File.

A list of SID variables available by State is provided under SID Database Documentation. This section also includes a detailed description of each SID variable. The SID excludes data elements that could directly or indirectly identify individuals.

Thirty-six States now participate in the SID (Select to access contact information for the participating data organization in these States):

Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Illinois, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, Nevada, New Jersey, New York, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Vermont, Washington, West Virginia, and Wisconsin.

Twenty of the thirty-six States make SID files available for purchase through the HCUP Central Distributor. These States include Arizona, California, Colorado, Florida, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Nebraska, New Jersey, New York, North Carolina, Oregon, South Carolina, Utah, Washington, West Virginia, and Wisconsin. The HCUP Central Distributor can also provide information on how to obtain SID files from the other sixteen States.

The SID are well suited for research that requires complete enumeration of hospitals and discharges within market areas or States, that investigates questions unique to a State, or that requires data from two or more States.

Recent studies using the SID include:

• Andrews R, Elixhauser A. Access to Major Therapeutic Procedures: Are Hispanics Treated Differently than Non-Hispanic Whites? Ethnicity & Disease 2000;10(3):59-69
• Basu J and Friedman B. Preventable Illness and Out-of-Area Travel of Children in New York Counties. Health Economics 2001;10(1):67-78
• Brooks JM, McClellan M, Wong HS. The marginal benefits of invasive treatments for acute myocardial infarction: Does insurance coverage matter? Inquiry 2000;37(1):75-90
• Gross, CP, Steiner CA, Bass EB, et al. Relation Between Prepublication Release of Clinical Trial Results and the Practice of Carotid Endarterectomy. Journal of the American Medical Association 2000;284(22):2886-93
• Wong HS, Hellinger FJ. Conducting Research on the Medicare Market: The Need for Better Data and Methods. Health Services Research 2001;36(1 pt. 2):291-308

More publications from the HCUP Database lists recent research using HCUP data.

For twenty of the thirty-six HCUP States, SID files for 1995-2002 are available through the AHRQ-sponsored HCUP Central Distributor. The HCUP Central Distributor can provide more detailed, descriptive information on the SID and assist purchasers in completing the application. Information on how to obtain uniformly formatted SID files from the other sixteen States is also available from the HCUP Central Distributor.

For answers to commonly asked questions regarding HCUP databases and tools, please review the Frequently Asked Questions. If you cannot find an answer to your question, please contact HCUP User Support Staff.

To reach HCUP User Support, please contact us by e-mail or phone:

• e-mail: hcup@ahrq.gov
• Phone (toll free): 1-866-290-HCUP

We review messages daily and will respond to all inquiries within 3 business days.