The Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS) featuring 2013 data is now available. The NIS is the largest all-payer inpatient care database in the United States.

The NIS is nationally representative of all short-term, non-Federal hospitals in the U.S. It is drawn from the HCUP State Inpatient Databases (SID)and includes more than 7 million hospital discharges from 47 States and the District of Columbia. Weighted, it approximates more than 36 million hospital stays. The NIS includes patients from all payer types, including Medicare, Medicaid, private insurance, and the uninsured.

Starting with database year 2012, the NIS was redesigned to improve national estimates. The new design consists of a "sample of discharges from all hospitals" (over 4,300) in HCUP, equal to approximately 20 percent of all discharges in U.S. community hospitals. Prior to 2012, the NIS was comprised of a 20 percent "sample of U.S community hospitals" and included 100 percent of discharges from those hospitals. This and other changes to the NIS' design will result in even more accurate national estimates, better data confidentiality, and reductions in sampling error.

AHRQ renamed the "Nationwide Inpatient Sample" to the "National Inpatient Sample" to signify this change. More information about the NIS redesign can be found in the NIS Redesign Final Report.

The NIS can be used by researchers and policymakers to identify, track, and analyze national trends in healthcare utilization, access, charges, quality, and outcomes. The vast size of the NIS enables analyses of infrequent conditions, uncommon treatments, and special patient populations.

As part of the HCUP database family, the NIS is considered by health services researchers to be one of the most reliable and affordable databases for studying important healthcare topics.

The 2013 NIS can be purchased through the HCUP Central Distributor, and select statistics can be accessed via HCUPnet. Additional information is located on the NIS Overview Page.