Healthcare Cost and Utilization Project (HCUP)
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Find complete program information on the HCUP-US website.
Overview of HCUP
The AHRQ Healthcare Cost and Utilization Project (HCUP) is a family of databases, software tools, and related products developed through a federal-state-Industry partnership with state data organizations, hospital associations, and private data organizations from 48 states and the District of Columbia. HCUP includes the near universe of encounter-level inpatient, emergency department, and ambulatory surgery data, regardless of the patient’s age, diagnosis, or expected payer, from all nonfederal acute care hospitals in participating states.
Information on the records includes patient demographics, all-listed diagnoses and procedures, origin of admission, expected payer (e.g., Medicare, Medicaid, private insurance, self-pay, no charge), hospital charges, and discharge disposition.
Produced annually, these databases enable research on a broad range of health policy issues, including cost and quality of health services, medical practice patterns, access to healthcare programs, and outcomes of treatment at the national, state, and local market levels.
The AHRQ HCUP databases are based on the data collection efforts of data organizations in participating States that have partnered with AHRQ.
HCUP Databases
National (Nationwide) Inpatient Sample (NIS)
The National (Nationwide) Inpatient Sample (NIS) is the largest publicly available all-payer hospital inpatient care database in the United States. Researchers and policymakers use NIS data to identify, track, and analyze trends in health care utilization, access, charges, quality, and outcomes.
Kids' Inpatient Database (KID)
The Kids' Inpatient Database (KID) is composed of hospital inpatient stays for children and is specifically designed to allow researchers to study a broad range of conditions and procedures related to children's health. The KID is produced every 3 years. Researchers and policymakers can use KID data to identify, track, and analyze healthcare utilization, access, charges, quality, and outcomes.
Nationwide Readmissions Database (NRD)
The Nationwide Readmissions Database (NRD) is a unique and powerful database designed to support various types of analyses of national readmission rates for all payers and uninsured individuals. This database addresses a large gap in health care data—the lack of nationally representative information on hospital readmissions for all ages.
Nationwide Emergency Department Sample (NEDS)
The Nationwide Emergency Department Sample (NEDS) captures information on emergency department (ED) visits that do not result in an admission as well as ED visits that result in an admission to the same hospital. The NEDS enables analyses of ED utilization patterns and supports public health professionals, administrators, policymakers, and clinicians in their decisionmaking regarding this critical source of care.
Nationwide Ambulatory Surgery Sample (NASS)
The Nationwide Ambulatory Surgery Sample (NASS) is the only all-payer ambulatory surgery database in the United States, producing national estimates of major ambulatory surgery encounters performed in hospital-owned facilities. Researchers and policymakers use NASS to study trends of ambulatory surgery utilization, access, and outcomes.
State Inpatient Databases (SID)
The State Inpatient Databases (SID) are a set of hospital databases containing the universe of the inpatient discharge records from participating States, translated into a uniform format to facilitate multi-State comparisons and analyses. Researchers and policymakers use the SID to investigate questions and identify trends unique to one State, to compare data from two or more States, and to conduct market area research or small area variation analyses.
State Emergency Department Databases (SEDD)
The State Emergency Department Databases (SEDD) are a set of databases that capture discharge information on all emergency department visits that do not result in an admission. The SEDD combined with SID discharges that originate in the emergency department are well suited for research and policy questions that require complete enumeration of hospital-based emergency departments within market areas or states.
State Ambulatory Surgery and Services Databases (SASD)
The State Ambulatory Surgery and Services Databases (SASD) include encounter-level data for ambulatory surgery and other outpatient services from hospital-owned facilities. In addition, some states provide data for ambulatory surgery and outpatient services from non–hospital owned facilities. The SASD is well suited for analyzing trends in ambulatory surgery utilization, access, and outcomes.
AHRQ HCUP nationwide and state databases from participating states can be purchased through the Online HCUP Central Distributor.
Research Tools and Software for Administrative Data
AHRQ Quality Indicators
AHRQ Quality Indicators (QIs) are measures of healthcare quality that use hospital inpatient administrative data and can be used to highlight potential quality concerns, identify areas that need further study and investigation, and track changes over time.
Other AHRQ HCUP Tools and Software
- Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses.
- Clinical Classifications Software Refined (CCSR) for ICD-10-PCS Procedures.
- Chronic Condition Indicator Refined for ICD-10-CM Diagnoses (CCIR).
- Elixhauser Comorbidity Software Refined for ICD-10-CM Diagnoses.
- Procedure Classes Refined for ICD-10-PCS Procedures.
- Surgery Flags for Services and Procedures.
- Cost-to-Charge Ratio (CCR) Files.
- Hospital Market Structure (HMS) Files.
- HCUP Supplemental Variables for Revisit Analyses.
- American Hospital Association (AHA) Linkage Files.
AHRQ HCUP Statistical Briefs
AHRQ HCUP Statistical Briefs present simple descriptive statistics on a variety of topics including specific medical conditions as well as hospital characteristics, utilization, quality, and cost.
Other AHRQ HCUP Publication Searches
Search for peer-reviewed articles and other reports based on HCUP data or products.
Send Questions and Comments to HCUP@ahrq.gov.
