2009 Nationwide Inpatient Sample released

Research Activities, August 2011, No. 372

The Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) featuring 2009 data was recently released by the Agency for Healthcare Research and Quality (AHRQ). The NIS is the largest all-payer inpatient care database in the United States and is updated annually. It is available from 1988 to 2009, allowing analysis of trends over time. The 2009 NIS contains data from approximately 8 million hospital stays drawn from more than 1,000 community hospitals in 44 States. The data can be weighted to produce national estimates, allowing researchers and policymakers to use it to identify, track, and analyze national trends in health care use, access, charges, quality, and outcomes.

The NIS is considered by health services researchers to be one of the most reliable databases for studying important health care topics. Its vast size enables analyses of infrequent conditions, such as rare cancers; uncommon treatments, such as organ transplantation; and special patient populations, like the uninsured. Its size also allows for the study of topics at both national and regional levels. In addition, NIS data are standardized across years to facilitate ease of use. The NIS 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). For nearly 60 percent of the hospitals, the NIS includes identifiers that allow linkages to the American Hospital Association's Annual Survey Database.

The NIS is nationally representative of all short-term, non-Federal hospitals in the United States. It approximates a 20 percent stratified sample of hospitals in the United States and is drawn from the HCUP State Inpatient Databases, which include 95 percent of all discharges in the United States. The NIS includes all patients from each sampled hospital, regardless of payer—including persons covered by Medicare, Medicaid, or private insurance, and the uninsured.

The 2009 NIS can be purchased through the HCUP Central Distributor at Healthcare Cost and Utilization Project (HCUP) . Statistics from the 2009 NIS are available at the HCUPNet Web site, a free online query system.

More information about the NIS and other HCUP products can be found on the HCUP-US Web site at Healthcare Cost and Utilization Project (HCUP) .

Current as of August 2011
Internet Citation: 2009 Nationwide Inpatient Sample released: Research Activities, August 2011, No. 372. August 2011. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/news/newsletters/research-activities/aug11/0811RA29.html