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Overview of the Kids' Inpatient Database (KID)
The Kids' Inpatient Database (KID) is a set of pediatric hospital inpatient databases included in the HCUP family. These databases are created by AHRQ through a Federal-State-Industry partnership.
The Kids' Inpatient Database

The Kids' Inpatient Database (KID) is part of a family of databases and software tools developed for the Healthcare Cost and Utilization Project (HCUP). The KID is the only all-payer database for children. Unweighted, it contains data from approximately 3 million pediatric discharges each year. Weighted, it estimates roughly 7 million hospitalizations.

Developed through a Federal-State-Industry partnership sponsored by the Agency for Healthcare Research and Quality, HCUP data inform decisionmaking at the national, State, and community levels.

This page provides an overview of the KID. For more details, see KID Database Documentation and the Introduction to the KID, 2009 (PDF file, 795 KB; HTML).


The KID yields national estimates of hospital inpatient stays for patients younger than 21 years of age. The unique design of the KID enables national and regional studies of common and rare pediatric conditions.

The KID can be used to identify, track, and analyze national trends in health care utilization, access, charges, quality, and outcomes.

KID data are available every three years from 1997 through 2009, which allows researchers to analyze trends over time. The number of States in the KID has grown from 22 in the first year (1997) to 44 in 2009.

Key features of the most recent KID database year (2009) include:
  • A sample of pediatric discharges from over 2,500 to 4,000 U.S. community hospitals (defined as short-term, non-Federal, general and specialty hospitals, excluding hospital units of other institutions)
  • A large sample size, which enables analyses of common and rare conditions (e.g. congenital anomalies), uncommon treatments, and organ transplantation
  • Charge information on all patients, including children covered by Medicaid, or private insurance, as well as those who are uninsured
  • Hospital identifiers for many States that permit linkages to the American Hospital Association (AHA) Annual Survey Database (Health Forum, LLC © 2012) and county identifiers that permit linkages to the Area Resource File.
Free HCUP Tools & Software are also available to identify preventable hospitalizations, estimate costs, assess quality of care and patient safety, categorize diagnoses and procedures, and identify comorbidities.

Information on the previous releases of the KID may be found in the Introduction to the KID (PDF file, 795 KB; HTML).
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The KID contains clinical and resource-use information that is included in a typical discharge abstract, with safeguards to protect the privacy of individual patients, physicians, and hospitals (as required by data sources). It contains more than 100 clinical and nonclinical data elements for each hospital stay, including:
  • Primary and secondary diagnoses and procedures
  • Admission and discharge status
  • Patient demographics (e.g., sex, age, race, median income for ZIP Code)
  • Hospital characteristics characteristics (e.g., ownership, size, teaching status)
  • Expected payment source
  • Total charges
  • Length of stay
  • Severity and comorbidity measures
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As a uniform, multi-State database, the KID promotes comparative studies of health care services and supports health care policy research on a variety of topics, including:
  • Utilization of health services by special populations
  • Hospital stays for rare conditions
  • Variations in medical practice
  • Health care cost inflation
  • Medical treatment effectiveness
  • Regional and national analyses
  • Quality of care
  • Impact of health policy changes
  • Access to care
The KID is used in a variety of publications:

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Spanning more than 10 years of data, the KID can be used for longitudinal analyses. However, the database has undergone changes over time, including the sampling and weighting strategy used. To facilitate multi-year analyses, the KID Supplemental Files (KID-Trends) were developed. These files use an alternate set of KID discharge weights for the 1997 KID. They contain revised trend weights and data elements that are consistently defined across data years. Trend analyses after 1999 do not need the KID-Trends.
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The KID is released every 3 years, beginning with the 1997 data year; the most recent release is the 2009 KID. The databases are available for purchase through the HCUP Central Distributor.

Prior to purchasing HCUP data, all individuals are required to take the online HCUP Data Use Agreement Training Course, and users of the KID must read and sign the Data Use Agreement for Nationwide Databases (PDF file, 50 KB; HTML).

Instructions for purchasing the KID are available in the Kids' Inpatient Database (KID) Application Kit (PDF file, 130 KB).

Questions regarding purchasing databases can be directed to the HCUP Central Distributor:

Telephone: (866) 556-4287 (toll free)
Fax: (866) 792-5313 (toll free)

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The KID is distributed as fixed-width ASCII formatted data files compressed with WinZip®. To load and analyze the KID data on a computer, you will need the following:

  • A DVD drive
  • A hard drive with 15 gigabytes of space available
  • A third-party zip utility such as ZIP Reader, 7-Zip, or WinZip®
  • SAS®, SPSS®, Stata® or similar analysis software
The data set includes weights for producing national and regional estimates. KID documentation and tools, including programs for loading the ASCII file into SAS, SPSS, or Stata, are also available on the KID Database Documentation page.

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Internet Citation: HCUP Databases. Healthcare Cost and Utilization Project (HCUP). December 2013. Agency for Healthcare Research and Quality, Rockville, MD.
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Last modified 12/11/13