To inform decisionmaking, scientifically sound and standardized databases and tools for using them are needed. The Healthcare Cost and Utilization Project (HCUP) is a family of health care databases and related software tools and products developed through a Federal-State-Industry partnership. The Agency for Healthcare Research and Quality (AHRQ) sponsors HCUP, and this Fact Sheet summarizes available HCUP resources.
Databases / Web-based HCUPnet / Software Tools / Recent Research / For More Information
The unprecedented volume and pace of change in the U.S. health care system and the fact that changes are not occurring uniformly across the country require a new information paradigm. Scientifically sound, standardized databases at the national, regional, and State levels and tools for using them are needed to inform decisionmaking. The Healthcare Cost and Utilization Project (HCUP) is designed to fill this niche.
HCUP is a Federal-State-industry partnership to build a standardized, multistate health data system and companion set of complementary resources. HCUP databases are a family of longitudinal, administrative databases—including State-specific hospital-discharge databases and a national sample of discharges from community hospitals.
The Agency for Healthcare Research and Quality (AHRQ) maintains HCUP and has taken the lead in making the databases publicly available and developing Web-based products and software tools.
HCUP databases serve a unique function and are being tapped by analysts and researchers interested in hospital utilization, access, charges, quality, and outcomes. Researchers rely on HCUP data to identify, track, analyze, and compare trends at the national, regional, and State levels. Because of their large size, the HCUP databases are used to describe patterns of care for rare as well as common diseases; analyze infrequent as well as common hospital procedures; and track utilization for population subgroups, such as minorities, children, women, and the uninsured.
HCUP databases contain a core set of clinical and nonclinical information on all patients, regardless of payer—including persons covered by Medicare, Medicaid, private insurance, and the uninsured—translated into a uniform format to facilitate both multistate and national/State comparisons and analyses.
HCUP data users must agree to certain conditions: the databases can be used only for research and statistical purposes, and institutions cannot be identified in publications.
Individual data sets from 36 participating States comprise the 2000 SID:
| Arizona* California* Colorado* Connecticut Florida* Georgia Hawaii Illinois Iowa* | Kansas Kentucky* Maine* Maryland* Massachusetts* Michigan* Missouri Minnesota Nebraska* |
Nevada New Jersey* New York* North Carolina* Ohio Oregon* Pennsylvania Rhode Island South Carolina* | South Dakota Tennessee Texas Utah* Vermont Virginia Washington* West Virginia* Wisconsin* |
*States that make their data files available through the HCUP Central Distributor as of July 2003.
Each data set contains the universe of that State's non-Federal hospital discharge abstracts. In aggregate, the SID represent approximately 80 percent of all U.S. hospital discharges, totaling over 29 million inpatient discharge abstracts. The SID are particularly well-suited for policy inquiries unique to a specific State, studies comparing two or more States, market area research, and small area variation analyses.
SID data years currently available: 1995-2002.
How to order: As of July 2003, 20 States make their inpatient databases available through the AHRQ-designated HCUP Central Distributor, Social and Scientific Systems, Inc. Users should contact:
HCUP Central Distributor
Social and Scientific Systems, Inc.
8757 Georgia Avenue, Suite 1200
Silver Spring, MD 20910-3714
Phone: (866) 556-4287 (toll free)
Fax: (301) 628-3201
E-mail: hcup@s-3.com
The HCUP Central Distributor also provides information on how to obtain uniformly formatted data from the other SID States. AHRQ is working with these States with the aim of providing centralized access for all SID States. Information on ordering SID also may be found on the AHRQ Web site.
Select to download the SID Application Kit.
Individual data sets from 18 participating States comprise the 2002 SASD:
| Colorado* | New York* |
| Connecticut | North Carolina |
| Florida* | Pennsylvania |
| Kentucky* | South Carolina |
| Maine | Tennessee |
| Maryland* | Utah* |
| Minnesota | Vermont |
| Missouri | Wisconsin* |
| Nebraska* | |
| New Jersey* |
*States that make their data files available through the HCUP Central Distributor as of July 2003.
All SASD capture surgeries performed on the same day in which patients are admitted and released from hospital-affiliated ambulatory surgery sites. Some SASD contain records from freestanding surgery centers as well.
The SASD are well suited for research that requires complete enumeration of hospital-based ambulatory surgeries within market areas or States. Analysts and researchers use SASD to compare inpatient and outpatient ambulatory surgery patterns; to conduct market area research or small area variation analyses; and to identify State-specific trends in ambulatory surgery utilization, access, charges, and outcomes.
SASD data years currently available: 1997-2003.
How to order: As of July 2003, seven States make their ambulatory surgery databases available through the AHRQ-designated HCUP Central Distributor. The HCUP Central Distributor also provides information on how to obtain uniformly formatted data from the other SASD States. AHRQ is working with these States with the aim of providing centralized access for all SASD States. Information on ordering SASD also may be found on the AHRQ Web site.
Select to download the SASD Application Kit.
The NIS is a stratified probability sample of hospitals drawn from the SID. The NIS is designed to approximate a 20-percent sample of U.S. community hospitals. NIS 2002 includes over 7 million inpatient discharges from about 986 hospitals in 36 States. It is the largest all-payer inpatient database in the United States.
The NIS is ideal for developing national estimates, for analyzing national trends, providing benchmark statistics that can be compared with regional and State level statistics, and for research that requires a large sample size.
NIS data years currently available: 1988-2002.
How to order: NIS 2001 may be purchased for $200 in a set of two CD-ROMs with accompanying documentation from the HCUP Central Distributor. The HCUP Central Distributor can also provide information on how to purchase NIS CD-ROM data sets for earlier years (beginning 1988). Prices vary by data year and, as of August 2004, range from $160 to $322.
This dataset, drawn from the SID, is the first research database exclusively concerned with inpatient care of children and adolescents in the Nation's community hospitals. The KID is the only dataset on hospital use, outcomes, and charges for children, including newborns, regardless of whether they were privately insured, received public assistance, or had no health insurance.
KID data years currently available: 1997 and 2000.
How to order: KID 1997 and KID 2000 may be purchased on CD-ROM for $200 each with accompanying documentation from the AHRQ-designated Central Distributor. Updates on availability of additional data years and further information on ordering the KID also may be found on the AHRQ Web site.
HCUP data include over 100 variables,
such as:
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HCUPnet is an interactive, Web-based service designed for Federal and State policymakers, health plan executives, and others who need to identify, analyze, and compare hospital inpatient statistics at national, regional, and State levels. HCUPnet provides inpatient data from the NIS, KID. In addition, State-level information is available from 22 States.
Menu-driven HCUPnet has many enhanced features to help users get answers to questions about hospital care more quickly including: "Instant Tables" that give statistics on the most common conditions and procedures in U.S. hospitals; the "National Bill" for total hospital charges for the most expensive conditions treated in U.S. hospitals; and 7-year (beginning 1993) trends in length of hospital stays, in-hospital deaths, charges, and other outcomes for all conditions and procedures treated in U.S. hospitals.
Data years currently available: 1997-2002.
Access to HCUPnet is available without charge on the AHRQ Web site at: www.ahrq.gov/hcupnet/.
AHRQ has developed three powerful software tools—AHRQ Quality Indicators, Clinical Classifications Software, and Comorbidity Software—that can be used, not only on HCUP databases, but on other administrative databases as well.
The AHRQ QIs are a set of quality indicators organized into three "modules," each of which measures quality associated with processes of care that occur in an outpatient or an inpatient setting. The AHRQ QIs, which expand and enhance the original HCUP Quality Indicators, can be used with information routinely collected by hospitals to highlight potential quality concerns, identify areas that need further investigation, and track changes over time.
All three AHRQ QI modules rely solely on hospital inpatient administrative data:
How to order: As of August 2004, three AHRQ QI modules can be downloaded directly, without charge, from the AHRQ Quality Indicators Web site:
Updates on availability of these modules and future refinements to the AHRQ QIs may be found on the AHRQ Quality Indicators Web site.
The CCS aggregates codes from the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) into a smaller number of clinically meaningful, relatively homogenous clusters, which are more amenable to certain statistical analyses. ICD-9-CM codes are the standard used in all institutionally based records (e.g., hospitals and outpatient surgery centers) and in insurance claims data. CCS can be applied to all ICD-9-CM data from 1980 to the present, including SID and NIS, with simple adjustments needed for data prior to 1993.
This "clinical grouper" helps users examine administrative data from a clinical perspective and is used in a variety of tasks, e.g., to develop clinically based profiles of resource use or to study patterns of diagnoses and procedures.
Access to the CCS, with user instructions, can be downloaded directly from the AHRQ HCUP site at www.hcup-us.ahrq.gov/toolssoftware/ccs/ccs.jsp.
HCUP's Comorbidity Software assigns variables that identify coexisting conditions on hospital discharge records using Diagnosis Related Groups (DRGs) and codes from the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Two SAS computer programs comprise the Comorbidity Software: One creates a format library that maps diagnosis codes into comorbidity indicators; the other applies the formats to an administrative dataset.
Access to Comorbidity Software with instructions can be downloaded from the AHRQ HCUP site at: www.hcup-us.ahrq.gov/toolssoftware/comorbidity/comorbidity.jsp.
Hospitalization in the United States, 1997 (HCUP Fact Book No. 1, AHRQ Publication No. 00-0031) gives a snapshot of hospital care in U.S. community hospitals in 1997.
Procedures in U.S. Hospitals, 1997 (HCUP Fact Book No. 2, AHRQ Publication No. 01-0016) provides a brief overview of procedures performed in the Nation's community hospitals in 1997.
Care of Women in U.S. Hospitals, 2000 (HCUP Fact Book No. 3, AHRQ Publication No. 02-0044) provides an overview of hospital care for women, including obstetric care, and compares hospital stays for women and men.
Care of Children and Adolescents in U.S. Hospitals: (HCUP Fact Book No. 4, AHRQ Publication No. 04-0004) examines hospital care for children using the Kids' Inpatient Database (KID).
Select for a comprehensive list of HCUP Research Notes. Other published statistics in tabular and chart form as well as summary analyses from various HCUP database releases and other documents are available online.
How to order: HCUP Fact Books and Research Notes are published by AHRQ and are also available online. Printed copies can be requested free of charge from the AHRQ Publications Clearinghouse (go to For More Information).
Authors: Boxer LK, JB Dimick, RM Wainess, et al.
Title: Payer status is related to differences in Access and outcomes of abdominal aortic aneurysm repair in the United States
Publication: Surgery 134:142-5
Date: 2003
Abstract: Access abstract.
Authors: Cowan JA, Jr., JB Dimick, RM Wainess, PK Henke, JC Stanley and GR Upchurch, Jr.
Title: Ruptured thoracoabdominal aortic aneurysm treatment in the United States: 1988 to 1998
Publication: J Vasc Surg 38:319-22
Date: 2003
Abstract: Access abstract.
Authors: Elixhauser A, C Steiner, I Fraser
Title: Volume thresholds and hospital characteristics in the United States
Publication: Health Aff (Millwood) 22:167-77
Date: 2003
Abstract: Access abstract.
Authors: Finlayson EV, PP Goodney, JD Birkmeyer
Title: Hospital volume and operative mortality in cancer surgery: a national study
Publication: Arch Surg 138:721-5; discussion, 726
Date: 2003
Abstract: Access abstract.
Authors: Fleishman JA, FH Hellinger
Title: Recent trends in HIV-related inpatient admissions 1996-2000: a 7-state study.
Publication: J Acquir Immune Defic Syndr 34:102-10
Date: 2003
Abstract: Access abstract.
Authors: Foxman B, Klemstine KL, Brown PD
Title: Acute pyelonephritis in U.S. hospitals in 1997. Hospitalization and in-hospital mortality
Publication: Ann Epidemiol 13(2):144-50
Date: 2003
Abstract: Access abstract.
Authors: General Accounting Office
Title: Hospital Emergency Departments: Crowded Conditions Vary among Hospitals and Communities
Publication Number: GAO-03-460
Date: March 14, 2003
Full Report: Available online at http://www.gao.gov/cgi-bin/getrpt?GAO-03-460
Authors: Holman RC, Belay ED, Curns AT, Schonberger LB, Steiner C.
Title: Kawasaki Syndrome hospitalizations among children in the United States, 1988-1997
Publication: Pediatrics 111(2):448
Date: 2003
Abstract: Access abstract.
Jiang HJ, D Stryer, B Friedman and R Andrews
Title: Multiple hospitalizations for patients with diabetes
Publication: Diabetes Care 26:1421-6
Date: 2003
Abstract: Access abstract.
Authors: Miller MR, Elixhauser A, Zhan C
Title: Patient safety events during pediatric hospitalizations
Publication: Pediatrics 111(6 Pt 1):1358-66
Date: 2003
Abstract: Access abstract.
Authors: Zhan C, Miller MR
Title: Excess length of stay, charges, and mortality attributable to medical injuries during hospitalization
Publication: JAMA 290(14):1868-74
Date: 2003
Abstract: Access abstract.
Select for a more comprehensive list of articles using HCUP data.
Additional information on HCUP databases, software, and other products is available from the AHRQ Web site at www.ahrq.gov or by E-mail at hcup@ahrq.gov.
An annotated listing of HCUP and other AHRQ publications may be found in the AHRQ Publications Catalog.
AHRQ Publications Clearinghouse
P. O. Box 8547
Silver Spring, MD 20907-8547
Phone: 800-358-9295 (toll-free)
Current as of August 2004
AHRQ Publication No. 02-P030
Released September 2002
Internet Citation:
Databases and Related Resources from HCUP. Fact Sheet, AHRQ Publication No. 02-P030, September 2002. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/data/hcup/datahcup.htm
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