Frequently Asked Questions

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The technical specifications for the indicator definitions have been separated out into ICD-9-CM and ICD-10-CM/PCS sets in v6.0 version. Detailed specifications, including specific International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes, Tenth Revision, Clinical Modification (ICD-10-CM/PCS) codes, Medicare Severity-Diagnosis Related Group (MS-DRGs), and/or patient age or sex are included in the documents.

The Technical Specifications for each QI module—Prevention Quality Indicators (PQI), Inpatient Quality Indicators (IQI), and Patient Safety Indicators (PSI) for version v6.0 ICD-9-CM and ICD-10-CM/PCS may be downloaded from the QI Website at:

No. You cannot use a dataset with mixed coding; that is, the software itself does not accept both ICD-9-CM and ICD-10-CM/PCS codes in the same dataset. However, you can split the dataset, such that the first three quarters of the data using ICD-9-CM diagnosis and procedure codes are separated from the last quarter of the data using ICD-10-CM/PCS diagnosis and procedure codes. ICD-9-CM v6.0 software, when available in the fall of 2016, or prior software can be used with the ICD-9-CM coded data; and ICD-10-CM/PCS v6.0 software can be used with ICD-10-CM/PCS coded data.

No, the AHRQ Quality Indicators (QIs) rely solely on inpatient hospital administrative data and do not assess quality of care for patients who are not admitted to a hospital. This is a known limitation of these indicators. Future versions of the AHRQ QIs may be developed that rely on additional data sources that will include patients receiving care in an outpatient basis or in an emergency room to generate a more comprehensive set of quality indicators to address other settings of care.

For more on the QIs, go to:

HCUPnet ( is an online query system that provides instant access to statistics from the Healthcare Cost and Utilization Project (HCUP), the largest set of all-payer health care databases for the United States that are publicly available.

By using HCUPnet's easy step-by-step query system, you can generate tables and graphs on national, regional, and community statistics including hospital readmissions and trends on hospital, emergency department, and ambulatory surgery use in the U.S. In addition, state-specific statistics are available for States that have agreed to participate in HCUPnet.

Information in HCUPnet includes:

  • Numbers of discharges/visits.
  • Charges.
  • Costs.
  • Length of stay.
  • Percent died.
  • Discharge status.

Details are provided for conditions, procedures, Diagnosis Related Groups (DRGs), and Major Diagnostic Categories (MDCs) by patient characteristics (age, sex, payer, community level income, and urban/rural location), hospital characteristics (ownership, bedsize, teaching status, and rural/urban location), and region of the country. Statistics can be found for all discharges or for operating room procedures only or for discharges that do not include maternal and newborns.

HCUPnet is part of the Healthcare Cost and Utilization Project (HCUP) of the Agency for Healthcare Research and Quality (AHRQ). HCUPnet generates statistics using data from HCUP's National (Nationwide) Inpatient Sample (NIS), the Kids' Inpatient Database (KID), the Nationwide Emergency Department Sample (NEDS), the Nationwide Readmissions Database (NRD), the State Inpatient Databases (SID), and the State Emergency Department Databases (SEDD). Statistics on ambulatory surgeries are available for the combination of states in the State Ambulatory Surgery and Services Databases (SASD).

These databases and HCUPnet would not be possible without the statewide data collection projects that provide data to HCUP:

For more information on purchasing HCUP databases to conduct analyses not possible through HCUPnet go to the HCUP Central Distributor website at

The Healthcare Cost and Utilization Project (HCUP, pronounced "H-Cup") is a family of health care databases and related software tools and products developed through a Federal-State-Industry partnership and sponsored by the Agency for Healthcare Research and Quality (AHRQ). HCUP databases bring together the data collection efforts of State data organizations, hospital associations, private data organizations, and the Federal Government to create a national information resource of patient discharge-level health care data.

HCUP includes the largest collection of longitudinal hospital care data (inpatient, emergency department, ambulatory surgery) in the United States, with all-payer, encounter-level information beginning in 1988. HCUP is derived from administrative data originally collected for billing purposes. For more information about HCUP, go to:

The HCUP databases enable research on a broad range of health policy issues, including cost and quality of health services, medical practice patterns, access to health care programs, and outcomes of treatments at the national, State, and local market levels. Many of the HCUP databases are available for purchase through the HCUP Central Distributor after completing the online Data Use Agreement (DUA) training and submitting the HCUP DUA at

Information on HCUP databases is at Information about obtaining HCUP data is at

HCUP offers free software tools that facilitate use of the data, including HCUPnet, an online query system that provides immediate access to statistics on hospital inpatient, emergency department, and ambulatory surgery use, cost, and readmissions. Information on HCUP tools and software is at

HCUP Fast Stats provide easy access to the latest HCUP-based statistics for health information topics using visual statistical displays at

HCUP offers online reports, including HCUP Statistical Briefs which present simple, descriptive statistics on a variety of specific, focused topics. Information on HCUP reports is at Published studies using HCUP can be found at

HCUP is a family of databases, software tools and products. Because there are a lot of components to this project, a user may need help understanding the project or how to apply it to his or her work. To this end, HCUP offers a variety of user assistance:

  • The HCUP User Support site—has comprehensive information about the project.
  • Instructor-led presentations and training that explain various parts of the project.
  • The Calendar of Events lists seminars, panels, posters, Webinars, exhibits and workshops that HCUP periodically offers to help you learn about HCUP and advance your use and understanding.
  • Online tutorials—HCUP offers a number of electronic courses to help users understand the project and how it can be used for research.
  • HCUP Technical Assistance—Contact HCUP User Support by email at or call (toll-free) 1-866-290-HCUP (4287) with questions regarding the application of an HCUP tool or product to your work. Staff reviews messages daily and responds to inquiries within 3 business days.

HCUP databases include:

  • The Nationwide Inpatient Sample (NIS) (produced annually starting with 1988 data year) has inpatient data from a nationwide sample that currently contains data on more than 7 million annual hospital stays that can be weighted to make national estimates.
  • The Kids' Inpatient Database (KID) (produced every 3 years starting with 1997 data year) is a nationwide sample of about 3 million pediatric inpatient discharges each year that can be weighted to make national estimates for pediatric care.
  • The Nationwide Emergency Department Sample (NEDS) (produced annually starting with 2006 data year) is a nationwide sample of nearly 30 million records currently from about 1,000 EDs.
  • The State Inpatient Databases (SID) (starting in 1995) contain the universe of inpatient discharges from individual states.
  • The State Ambulatory Surgery Databases (SASD) (starting in 1997) contain data on encounters from hospital-owned ambulatory surgery facilities, and in some States, from non-hospital-owned facilities.
  • The State Emergency Department Databases (SEDD) (starting in 1999) contain data from hospital-affiliated emergency departments for visits that do not result in hospitalizations.

Many of the HCUP databases are available for purchase through the HCUP Central Distributor. More information is available at

The Consumer Assessment of Healthcare Providers and Systems (CAHPS®) program is a multi-year initiative of the Agency for Healthcare Research and Quality (AHRQ) to develop surveys of patients' experiences with the healthcare they receive from health plans, providers, and facilities such as hospitals, in-center hemodialysis facilities, and home health agencies. The CAHPS program also houses a database for voluntarily submitted survey data from health plans and group practices to support; research quality improvement. Many CAHPS surveys are mandated by the Centers for Medicare and Medicaid Services for public reporting and in pay-for-performance initiatives.

For more information, go to the CAHPS® website at

CAHPS® surveys are designed to capture patients' reports and ratings of their experiences with health care services. Specifically, the surveys probe domains that meet the following criteria:

  • Consumers and patients are the best and/or only source of information. CAHPS® surveys do not attempt to collect information that can be gathered more effectively through other means (e.g., through medical records or from physicians).
  • Consumers and patients have identified the survey domains as being important. The CAHPS® program devotes substantial resources to identifying and confirming the issues that are salient to consumers and influence their decisions, and that the survey questions are meaningful and comprehensible to consumers.

Examples of domains covered by CAHPS® surveys include getting timely appointments, care and information; how well providers communicate with patients; providers' use of information to coordinate care; helpful, courteous and respectful office staff, and customer service.

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