National (Nationwide) Inpatient Sample (NIS)

Purveyor: Agency for Healthcare Research and Quality

Years in the DataCore: 1988-2016

Years of data owned: 1988-2016

Unit of data: Hospital discharge

Dataset website: https://www.hcup-us.ahrq.gov/db/nation/nis/nisdbdocumentation.jsp 

General description: The NIS is the largest publicly available all-payer inpatient healthcare database in the United States, yielding national estimates of hospital inpatient stays. Unweighted, it contains data from more than 7 million hospital stays each year. Weighted, it estimates more than 35 million hospitalizations nationally. 

Kids' Inpatient Database (KID)

Purveyor: Agency for Healthcare Research and Quality

Years in the DataCore: 1997, 2000, 2003, 2006, 2009, 2012, 2016

Years of data owned:1997, 2000, 2003, 2006, 2009, 2012, 2016

Unit of data: Hospital Discharge

Dataset website: https://www.hcup-us.ahrq.gov/db/nation/kid/kiddbdocumentation.jsp 

General description: The KID is the largest publicly available all-payer pediatric inpatient care database in the United States. Unweighted, it contains data from approximately 3 million pediatric discharges each year. Weighted, it estimates roughly 7 million hospitalizations. 

Nationwide Readmissions Database (NRD)

Purveyor: Agency for Healthcare Research and Quality

Years in the DataCore: 2010-2016

Years of data owned: 2010-2016

Unit of data: Hospital Discharge

Dataset website: https://www.hcup-us.ahrq.gov/db/nation/nrd/nrddbdocumentation.jsp 

General description: The NRD is a unique and powerful database designed to support various types of analyses of national readmission rates for all payers and the uninsured. This database addresses a large gap in healthcare data: the lack of nationally representative information on hospital readmissions for all ages. Unweighted, the NRD contains data from approximately 17 million discharges each year. Weighted, it estimates roughly 36 million discharges. 

Nationwide Emergency Department Sample (NEDS)

Purveyor: Agency for Healthcare Research and Quality

Years in the DataCore: 2006-2016

Years of data owned: 2006-2016

Unit of data: Hospital Discharge

Dataset website: https://www.hcup-us.ahrq.gov/db/nation/neds/nedsdbdocumentation.jsp

General description: The NEDS is the largest all-payer emergency department (ED) database in the United States, yielding national estimates of hospital-based ED visits. Unweighted, it contains data from approximately 31 million ED visits each year. Weighted, it estimates roughly 143 million ED visits.

Organization website: https://www.ahrq.gov

HCUP website: https://www.ahrq.gov/data/hcup/index.html

Licensing and access

All users of HCUP data must complete the HCUP Data Use Agreement (DUA) Training Course and sign an HCUP DUA before receipt of the data. See this website for further information: https://www.hcup-us.ahrq.gov/tech_assist/dua.jsp.