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National Inpatient Sample (NIS) - Restricted Access Files

Metadata Updated: July 26, 2023

The Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS) is the largest publicly available all-payer inpatient care database in the United States. The NIS is designed to produce U.S. regional and national estimates of inpatient utilization, access, cost, quality, and outcomes. Unweighted, it contains data from more than 7 million hospital stays each year. Weighted, it estimates more than 35 million hospitalizations nationally. Developed through a Federal-State-Industry partnership sponsored by the Agency for Healthcare Research and Quality (AHRQ), HCUP data inform decision making at the national, State, and community levels.

Starting with the 2012 data year, the NIS is a sample of discharges from all hospitals participating in HCUP, covering more than 97 percent of the U.S. population. 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's large sample size enables analyses of rare conditions, such as congenital anomalies; uncommon treatments, such as organ transplantation; and special patient populations, such as the uninsured. NIS data are available since 1988, allowing analysis of trends over time.

The NIS inpatient data include clinical and resource use information typically available from discharge abstracts with safeguards to protect the privacy of individual patients, physicians, and hospitals (as required by data sources). Data elements include but are not limited to: diagnoses, procedures, discharge status, patient demographics (e.g., gender, age), total charges, length of stay, and expected payment source, including but not limited to Medicare, Medicaid, private insurance, self-pay, or those billed as ‘no charge’. The NIS excludes data elements that could directly or indirectly identify individuals.

Restricted access data files are available with a data use agreement and brief online security training.

Access & Use Information

Restricted: This dataset can only be accessed or used under certain conditions. License: See this page for license information.

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Metadata Created Date November 10, 2020
Metadata Updated Date July 26, 2023

Metadata Source

Harvested from

Additional Metadata

Resource Type Dataset
Metadata Created Date November 10, 2020
Metadata Updated Date July 26, 2023
Publisher Agency for Healthcare Research and Quality, Department of Health & Human Services
Identifier bae01dec-8c8a-48c0-8d22-e0f85f2edd8e
Data First Published 2021-02-13
Data Last Modified 2023-07-25
Rights N/A
Category Tag 16E15F51 D96E 4051 9124 75665Abdc6Ff "Human Health"
Public Access Level restricted public
Bureau Code 009:33
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Data Dictionary
Harvest Object Id f1812fad-17f1-4855-9db6-71e6a17404da
Harvest Source Id 651e43b2-321c-4e4c-b86a-835cfc342cb0
Harvest Source Title
Homepage URL
Program Code 009:072
Source Datajson Identifier True
Source Hash e560ffc8e8a920d2a94b024cec8c981b57bef110
Source Schema Version 1.1

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