NCHS Fact Sheet

July 2012

National Health Interview Survey

About NCHS

The CDC’s National Center for Health Statistics (NCHS) is the nation’s principal health statistics agency, providing data to identify and address health issues. NCHS compiles statistical information to help guide public health and health policy decisions.

Collaborating with other public and private health partners, NCHS employs a variety of data collection mechanisms to obtain accurate information from multiple sources. This process provides a broad perspective to help us understand the population’s health, influences on health, and health outcomes.

National Health Interview Survey

The National Health Interview Survey (NHIS) provides information annually on the health status of the U.S. civilian non-institutionalized population through confidential interviews conducted in households. The NHIS is the nation's largest household health survey. It provides data for analyzing health trends, determining barriers to care, and comparing health status, health related behaviors, and risk factors across racial and ethnic populations.

Health Topics Addressed

Health Status
Use of Health Services
Health Behaviors
Insurance Coverage
Access to Care
Measures of Functioning
Injuries
Immunizations
Conditions such as: Asthma, Diabetes, Heart Disease, Mental Health, and Cancer
Complementary and Alternative Medicine

Examples of NHIS Data

Source: National Health Interview Survey, 2011.

Findings in 2011:

The percentage of uninsured persons at the time of interview was 21.3 percent for persons aged 18-64 years and 7.0 percent for children under age 18.
A total of 46.3 million persons (15.1 percent) of all ages were uninsured at the time of the interview, 58.7 million (19.2 percent) had been uninsured for at least part of the year prior to the interview, and 34.2 million (11.2 percent) had been uninsured for more than a year at the time of the interview.
Among adults 19-25 years of age, the percent uninsured at the time of the interview decreased from 33.9 percent (10 million persons) in 2010 to 27.9 percent (8.4 million) in 2011.

Source: National Health Interview Survey,2011.

For both sexes combined, the prevalence of current asthma was lower among those under 15 years of age and persons 35 years of age and older.
For children under age 15, the prevalence of current asthma was higher among boys than girls. However, for age groups 15-34 years of age and 35 years of age and older, the prevalence of current asthma was higher among females than among males.

Other findings for 2011 include:

The percent of persons of all ages with a usual place to go for medical care was highest for non-Hispanic whites at 89.1 percent and lowest for Hispanics at 78.0 percent.
The percent of current smokers among adults 18 years and older, was highest for non-Hispanic whites at 21.2 percent and lowest for Hispanics at 12.3 percent.
The prevalence of diagnosed diabetes (based on self-report of physician diagnosis) was higher among non-Hispanic blacks and Hispanics than among non-Hispanic whites.

Wireless Substitution Data

In May and December of each year, the NHIS releases selected estimates of telephone coverage based on in-person interviews including whether anyone in the household has a wireless telephone. The inability to reach households with only wireless telephones (or with no telephone service) has potential implications for results from health surveys and other research conducted using random-digit-dial telephone surveys. Coverage bias may exist if there are differences between persons with and without landline telephones for the substantive variables of interest.

Results indicate that one-third of American homes (34.0 percent) had only wireless phones during the last half of 2011, an increase of 2.4 percentage points since the first half of 2011. In addition, nearly 6 in 10 of adults 25-29 years of age lived in households with only wireless telephones.
The prevalence of having five or more alcoholic drinks in 1 day during the past year among wireless-only adults (31.5 percent) was substantially higher than the prevalence among adults living in landline households (17.2 percent). Wireless-only adults were also more likely to be current smokers than were adults living in landline households.

Challenges and Future Opportunities

To improve the usefulness and accessibility of NHIS data by continuous improvements in data quality, relevance and reporting. Major projects include enhanced Web access for both current and historic NHIS data.

For further information about NCHS and its programs, visit the NCHS website, or call the Office of Planning, Budget and Legislation at 301-458-4100.

For further information on NHIS, visit the NHIS homepage.