Nationwide inpatient sample (NIS)
Title
Nationwide inpatient sample (NIS)
Description
The NIS is the largest publicly available all-payer inpatient care database in the United States. It contains data from approximately 8 million hospital stays each year. The 2012 NIS was redesigned. The new NIS is a sample of discharges from all hospitals participating in HCUP. For prior years, the NIS was a sample of hospitals. The NIS allows for weighted national estimates to identify, track, and analyze national trends in health care utilization, access, charges, quality, and outcomes.
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). The NIS excludes data elements that could directly or indirectly identify individuals.
Creator
Healthcare Cost & Utilization Project (HCUP)
, U.S. Department of Health and Human Services. Agency for Healthcare Research and Quality
, U.S. Department of Health and Human Services. Agency for Healthcare Research and Quality
Links
Collection
Microdata
Alternative Title
National inpatient sample (NIS), National (nationwide) inpatient sample (NIS)
Terms of Use
University of Toronto students, staff and faculty for research purposes only. Each user must sign a copy of the Data Use Agreement and complete the online Data Use Agreement Training Course at www.hcup-us.ahrq.gov.
License
Restricted
CD Number
1228 (1988 data), 1229 (1989 data), 1230 (1990 data), 1231 (1991 data), 1232 (1992 data), 1233 (1988-1992 documentation), 1234 (1993 data), 1235 (1993 documentation), 1236 (1994 data), 1237 (1994 documentation), 1238 (1995 data), 1239 (1995 documentation), 1240 (1996 data), 1241 (1996 documentation), 1242 (1997 data), 1243 (1997 documentation), 1244 (1997 release 2 data), 1245 (1997 release 2 documentation), 1246 (1998 data), 1247 (1998 documentation), 1248 (1999 data), 1249 (1999 documentation), 1250 (2000 data), 1251 (2000 documentation)
Data Collector
Healthcare Cost and Utilization Project (HCUP)
Collection Date
1988 to 2000
Distributor
Healthcare Cost and Utilization Project (HCUP)
Geographic Keywords
United States
Continent
North America
Mode of Data Collection
Administrative records
Notes
Available on CD-ROM at the Map & Data Library. Note the second release of the 1997 survey includes records that were omitted in the first release.
Keywords
Health
Time Period
1988-2000
Citation
Healthcare Cost & Utilization Project (HCUP)
, U.S. Department of Health and Human Services. Agency for Healthcare Research and Quality, “Nationwide inpatient sample (NIS),” MDL Data, accessed January 23, 2026, https://mdl-data.library.utoronto.ca/items/show/48.
