2012 National Healthcare Quality and Disparities Reports

Data Sources—Indian Health Service

Indian Health Service (IHS) National Data Warehouse (NDW)


U.S. Department of Health and Human Services, Indian Health Service.


NDW is the national repository for all IHS health care data and includes information on patient registration and visit encounters. Data are derived from various government (mostly the Resource Patient Management System) and commercial health care information systems. These are largely transaction-based systems used to support patient care. NDW is an upgraded version of the National Patient Information Reporting System.

Primary Content

NDW includes registration records and all encounter records dated October 1, 2000, to the present. Registration tables contain patient information, including name, demographic data, medical chart data, aliases, and insurance eligibility data. Encounter tables contain encounter information, including location of treatment, clinic, provider, medications, and diagnosis codes.

Population Targeted

NDW collects data on approximately 1.5 million American Indians and Alaska Natives who belong to 565 federally recognized tribes in 35 States.

Demographic Data

Age, gender, and American Indian and Alaska Native status.

Years Collected

1997 to present.



Geographic Estimates

National IHS service area estimates are available for the following IHS regions: Aberdeen, Alaska, Albuquerque, Bemidji, Billings, Nashville, Navajo, Oklahoma, Phoenix, and Tucson. Estimates exclude the Portland and California service areas.


Since no IHS inpatient facilities are located in either the Portland or California service areas, hospitalizations from these regions are not present in the data; the denominator is correspondingly reduced.

Contact Information

Agency home page: http://www.ihs.gov.

Data system home page: http://www.ihs.gov/NDW/.


Berger L, Garrett Sims LTJ. Identifying polypharmacy among older adults using IHS National Data Warehouse data. IHS Primary Care Provider 2010;35(10).

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Page last reviewed June 2013
Internet Citation: 2012 National Healthcare Quality and Disparities Reports: Data Sources—Indian Health Service. June 2013. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/research/findings/nhqrdr/nhqrdr12/datasources/ihs.html