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NIS File Specifications
The National (Nationwide) Inpatient Sample (NIS) is a set of longitudinal hospital inpatient databases included in the HCUP family. These databases are created by AHRQ through a Federal-State-Industry partnership.
 
NIS File Specifications

Each year of the NIS is comprised of the Core Data File and three or more additional files, in ASCII text format. A Hospital Weights File is always included. Severity Measures Files, Diagnosis and Procedure Groups Files, and database 10% Sample files are also included, depending on the year. The following links provide file specifications for the NIS including the dataset name, number of records, and record layout.
 
2016 NIS

Core File Hospital Weights File Severity Measures File Top



2015 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2014 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2013 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2012 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2011 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2010 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2009 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2008 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2007 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2006 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2005 NIS

Core File Hospital Weights File Severity Measures File Diagnosis and Procedure Groups File Top



2004 NIS

Core File Hospital Weights File 10% Sample File #1 10% Sample File #2 Severity Measures File Severity 10% Sample #1 Severity 10% Sample #2 Top



2003 NIS

Core File Hospital Weights File 10% Sample File #1 10% Sample File #2 Severity Measures File Severity 10% Sample #1 Severity 10% Sample #2 Top



2002 NIS

Core File Hospital Weights File 10% Sample File #1 10% Sample File #2 Severity Measures File Severity 10% Sample #1 Severity 10% Sample #2 Top



2001 NIS

Core File Hospital Weights File 10% Sample File #1 10% Sample File #2 Top



2000 NIS

Core File Hospital Weights File 10% Sample File #1 10% Sample File #2 Top



1999 NIS - Version 2

Core File Hospital Weights File 10% Sample File #1 10% Sample File #2 Top



1999 NIS - Version 1

Core File Hospital Weights File 10% Sample File #1 10% Sample File #2 Top



1998 NIS - Version 2

Core File Hospital Weights File 10% Sample File #1 10% Sample File #2 Top



1998 NIS - Version 1

Core File Hospital Weights File 10% Sample File #1 10% Sample File #2 Top



1997 NIS

Top



1996 NIS

Top



1995 NIS

Top



1994 NIS

Top



1993 NIS

Top



1992 - 1988 NIS

Top

Internet Citation: NIS File Specifications. Healthcare Cost and Utilization Project (HCUP). August 2018. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/db/nation/nis/nisfilespecs.jsp.
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Last modified 8/13/18