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National Healthcare Disparities Report, 2004

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National Health Interview Survey (NHIS)


U.S. Department of Health and Human Services, Centers for Disease Control and Prevention (CDC), National Center for Health Statistics (NCHS).

Mode of Administration

Personal interview in households using computer-assisted personal interviewing (CAPI), administered by professional interviewers, and conducted in English and Spanish (for CAPI, Spanish version was initiated in mid-1998).

Survey Sample Design

The NHIS uses a stratified multistage probability design that permits a continuous sampling of 358 primary sampling units (PSUs), with over-sampling of African Americans and Hispanics. A typical NHIS sample for the data collection years 1995–2004 consists of approximately 7,000 second-stage units (segments) within a PSU. The expected sample of 43,000 occupied respondent households yields a probability sample of about 111,000 persons. The survey is designed so that the sample scheduled for each week is representative of the target population and the weekly samples are additive over time.

Primary Survey Content

Information is obtained on demographic characteristics, illnesses, injuries, impairments, chronic conditions, utilization of health resources, health insurance, and other health topics. The core household interview asks about everyone in the household. Additional questions are asked of one sample adult and one sample child (under 18 years) per family in the household. The sample adult questionnaire includes chronic health conditions and limitations in activity, health behaviors, health care access, health care provider contacts, immunizations, and AIDS knowledge and attitudes. The sample child questionnaire includes questions about chronic health conditions, limitation of activities, health status, behavior problems, health care access and utilization, and immunizations. Child data are proxy-reported by a parent or other knowledgeable adult respondent. Adult sample person data are self-reported. Special modules are fielded periodically, and cover areas such as cancer, prevention, disability, and use of complementary and alternative medicine.

Population Targeted

Civilian noninstitutionalized population residing in the United States, all ages.

Demographic Data

Gender, age, race/Hispanic ethnicity, education, income, marital status, place of birth, industry, and occupation.

Years Collected

Continuously since 1957. Current sample design began in 1995; current questionnaire design began in 1997.



Geographic Estimates

National; four U.S. Census Bureau regions; some of the 10 HHS regions, some States; metropolitan and nonmetropolitan areas.

Contact Information

Agency homepage:

Data system homepage:


See the 2002 National Health Interview Survey (NHIS) Public Use Data Release: NHIS Survey Description at



The information on this page is archived and provided for reference purposes only.


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