Welcome to the
National
Health Interview Survey Participant Information Page
If you have already been a survey participant,
thank you! If you have been notified that your household has been selected
for the National Health Interview Survey (NHIS) and you are thinking about
becoming a survey participant, we hope these answers to some frequently
asked questions will help you understand why your participation is so
important. In order for the results from the NHIS to accurately represent
the health of the nation, respondents selected must be from a random sample.
If you were selected to participate in this survey, your answers count
toward finding out about the health of our nation.
The National Center for Health Statistics (NCHS),
a part of the U.S. Centers for Disease Control and Prevention (CDC), is
responsible for this survey. It is a nationwide survey concerned with the
health of the U.S. population and factors that affect people’s health.
Frequently asked questions about the NHIS
from survey participants:
What is the National
Health Interview Survey?
Why is this survey
being conducted?
Why is it
important for me to participate?
What type of
information is collected?
Why ask questions about
age, race, ethnicity, and income?
How do I know this is a
legitimate survey?
Who asks the questions?
Do I have to participate in
the survey?
Who needs to
participate in the interview?
How long does it take?
Is my information kept
confidential?
How are NHIS data and
reports released to the public?
How can I contact you for
more information?
What is the National
Health Interview Survey?
The National Health Interview Survey (NHIS) is
the principal source of information on the health of the civilian
noninstitutionalized population of the United States and is one of the major
data collection programs of the National Center for Health Statistics (NCHS),
which is part of the U.S. Centers for Disease Control and Prevention (CDC).
NHIS data are collected through personal
household interviews. For over 50 years, interviewers from the U.S. Census
Bureau have visited American homes to ask about a broad range of health
topics. Survey results have been instrumental in providing data to track
health status, health care access, and progress toward achieving national
health objectives.
Click here to download a copy of the
NHIS brochure, which
provides more information about the survey.
Why is this survey
being conducted?
The main objective of the NHIS is to monitor
the health of the U.S. population through the collection and analysis of
data on a broad range of health topics. The National Health Survey Act of
1956 provided for a continuing survey and special studies to secure accurate
and current statistical information on the amount, distribution, and effects
of illness and disability in the United States and the services rendered for
or because of such conditions. The NHIS was initiated in July 1957.
Why is it
important to participate?
Your household was selected to represent
thousands of other households like yours. Your address is part of a
scientifically chosen sample. We cannot select anyone else if you do not
participate, which may mean that households like yours are underrepresented
in national estimates. These estimates are used by policy makers to
determine needs for health services in our country. By participating, you
perform a valuable public service for your family, community, and country.
What type of
information is collected?
The NHIS has several main sections. The Family
Core questionnaire collects information on everyone in the family, including
household composition; basic demographic characteristics such as age, sex,
race and ethnicity, and income; health insurance coverage; information for
linking to administrative data bases; and basic indicators of health status
and utilization of health care services.
In addition, from each family in the NHIS, one
sample adult and, if applicable, one sample child are randomly selected, and
information on each is collected with the Sample Adult Core and the Sample
Child Core questionnaires. Because some health issues are different for
children and adults, these two questionnaires differ in some items, but both
collect basic information on health status, health care services, and
health-related behavior.
Also, each year, supplemental questions are
added to collect more detailed information on core topics and/or to respond
to new public health data needs as they arise. These supplements are
sponsored by other agencies than NCHS.
Why ask questions
about age, race, ethnicity, and income?
Age, race and ethnicity, and income are often
associated with differences in health status and the use of health care
services. A major strength of this survey lies in the ability to analyze
health characteristics classified according to persons’ demographic and
socioeconomic characteristics. For example, this information is very useful
to analysts who are trying to understand differences in how we use health
care services and to enable planners to direct resources to subpopulations
most in need.
How do I know this is a
legitimate survey?
The National Center for Health Statistics
contracts with the U.S. Census Bureau, whose interviewers collect the survey
data. All personnel involved with the collection of data are employed by the
U.S. government. They have been trained by the U.S. Census Bureau according
to procedures specified by NCHS and have signed a statement guaranteeing the
confidentiality of your data. Each interviewer carries a badge identifying
him/her as a U.S. Census Bureau employee.
Who asks the
questions?
Data are collected through personal household
interviews conducted by interviewers employed and trained by the U.S. Census
Bureau according to procedures specified by NCHS.
Do I have to participate
in the survey?
Participation by those randomly selected for
the survey is very important to accurately represent all types of households
and families in the United States, regardless of health status. Survey
participation is voluntary; however, we cannot select anyone else to replace
you if you were selected and do not participate, which may mean that
households like yours are underrepresented in national estimates. The
confidentiality of your responses is assured under Section 308(d) of the
Public Health Service Act. Many people find the interview to be interesting
and enjoyable. The annual response rate of NHIS is nearly 90% of the
eligible households in the sample.
Who needs to
participate in the interview?
For the Family questionnaire, all adult
members of the household 17 years of age and over who are at home at the
time of the interview are invited to participate and to respond for
themselves. For children and for adults not at home during the interview,
information is provided by a responsible adult family member (18 years of
age and over) residing in the household.
For the Sample Adult questionnaire, one adult
per family is randomly selected; these individuals must respond for
themselves to the questions in this section unless they are physically or
mentally incapable of answering. In that case, a knowledgeable adult in the
family or a caretaker may answer the questions for the selected person.
Information for the Sample Child questionnaire
is obtained from a knowledgeable adult in the household.
How long does it
take?
The survey takes an average of about an hour
to do all the parts, depending on the number and health of your family
members.
Is my information kept
confidential?
The confidentiality of responses is assured
under Section 308(d) of the Public Health Service Act. The National Center
for Health Statistics has many procedures in place to prevent the disclosure
of your data to others. Some of these procedures include data encryption,
secure data networks, and many other security mechanisms following strict
federal mandates. Responses are collected by the U.S. Census Bureau and
securely transmitted to NCHS, where the data undergo edits and removal of
personal identifiers prior to being collected into public use files. The
collected data are used for research and statistical purposes only. When
analytic reports are prepared and released by NCHS staff, your answers have
been combined with those of many other respondents. No information that
could identify any individual is publicly released.
How are NHIS data and
reports released to the public?
Data from the NHIS, including your
contribution if you participated in the survey, are collected into microdata
files that are edited to remove all personal identifiers. These edited files
are released to the public through the NHIS website. The data from these
files are also statistically analyzed, and the results are published in
several types of reports that are released over the Internet or in journal
articles.
The collected data are used for research and
statistical purposes only. When analytical reports are prepared and released
by NCHS staff, individual answers have been combined with those of many
other respondents, which safeguards the privacy of the individuals who
responded to the survey. No information that could identify any individual
is publicly released.
More information
about the available microdata files and reports is found on our website
How can I contact you
for more information?
For more information about the NHIS, recent
reports, and data, please go to our website
or call or write to us at:
Division of Health Interview Statistics
National Center for Health Statistics
Centers for Disease Control and Prevention
3311 Toledo Road, Room 2217
Hyattsville, Maryland 20782-2003
(301) 458-4901 or (301) 458-4001
You may also email us at
NHIS@CDC.GOV
For publications and information:
Data Dissemination Branch
National Center for Health Statistics
Centers for Disease Control and Prevention
3311 Toledo Road, Room 5407
Hyattsville, Maryland 20782-2003
1 (800) 232-4636
NCHS Internet
home page
This page last reviewed
October 15, 2008
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