Purpose Of The Database And Study Design: HCUP-3 is a public-private partnership between the Federal and State governments and health care industry to produce health care data. The objectives of HCUP are to obtain data from statewide sources (principally State governments and hospital associations); design and develop a multi-state health care database for use in health services research and policy analysis; and release data to public and private users for a variety of purposes. HCUP-3 consists of two hospital inpatient databases: the HCUP-3 Nationwide Inpatient Sample (NIS) and the HCUP-3 State Inpatient Database (SID). These databases contain data elements that are similar to a typical discharge abstract.
Nature Of The Data Collected: Cross-sectional administrative and clinical records
Unit Of Analysis: Inpatient discharges
Data Collection Methods: The HCUP-3 NIS contains inpatient and hospital-based ambulatory surgery data from about 900 US hospitals, or about a 20 percent sample of hospitals. The NIS uses a stratified probability sample of hospitals, selected to be representative of US community hospitals as based on the American Hospital Association (AHA) Annual Survey. AHA defines community hospitals as non-Federal short-term general hospitals that are open to the public, as well as specialty hospitals. Short-term stays have an average length of less than 30 days. The AHA Annual Survey is used to stratify hospitals by several characteristics: ownership/control, bed size, teaching status, rural or urban location, and US region. Where possible, a 20 percent sample is drawn of each strata. The NIS contains records for all stays in the sampled hospitals. The sample was drawn from states including: Arizona, California, Colorado, Connecticut, Florida, Illinois, Iowa, Kansas, Maryland, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, South Carolina, Washington, and Wisconsin. The NIS includes core inpatient data elements. The HCUP-3 SID contains 100 percent of hospitals and discharges from State government and private data agencies with statewide inpatient data systems. The SID includes common inpatient data elements. After conversion of the submitted data to AHRQ and processing to create a uniform format, the processed tape is returned to the data source. Dissemination of the SID is controlled by the original data source. The identity of individual patients and physicians is not included in the records to protect their confidentiality. These databases are supplemented with data from sources including the AHA Annual Survey of Hospitals, the Area Resource File maintained by HRSA’s Bureau of Health Professions, and Bureau of the Census.
General Attributes: HCUP-3 was initiated on an annual basis in 1988. HCUP-1 data collection occurred in 1970 through 1977. HCUP-2 data collection spanned 1980 through 1987.
Major Data Constructs And Key Data Elements: Patient demographic, geographic, and payer characteristics; principal and secondary diagnoses; principal and secondary procedures; length of stay; total charges; admission and discharge status; and hospital characteristics.
Strengths And Weaknesses Of The Study Design And Database: HCUP-3 databases are available through public use tapes. HCUP documentation states that since the data were originally gathered for administrative purposes, there may be reliability and validity problems with some data elements. Additional problems cited include missing data, under-reporting of socially stigmatizing conditions such as mental illness or drug use, and under-reporting of minor procedures.
Gaps In The Data Collected And Factors Leading To The Gaps: None identified
Feasibility Of Linking With Other Databases: Linkage to other databases is feasible.
Process To Access The Database And Contact Person: The Nationwide Inpatient Sample can be purchased from NTIS. A confidentiality agreement must be signed. General questions about the database can be addressed to firstname.lastname@example.org. Information is also available through the HCUP website at: http://www.ahrq.gov.
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