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Frequently Asked Questions (FAQs)
NHANES is a nationally representative survey of adults and children in the United States. It is conducted by the National Center for Health Statistics (NCHS), which is part of the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Department of Health and Human Services (DHHS). We designed the survey to learn about the health and nutrition of people in the United States. Our survey is unique. It combines interviews with health measurements that are done in special Mobile Exam Centers. These centers travel across the country, each with their own highly trained teams of health staff. The teams use the most up-to-date methods and equipment for health exams and lab tests.
We use the data gathered in this survey to find out the number of people with certain health problems—for example, diabetes and high blood pressure. We look at diet and other habits that affect health, such as smoking and exercise. NHANES provides health and nutrition information about people of all ages in the United States. The data are also used by those who design health programs and services.
The National Health Survey Act, passed in 1956, provided the legislative authorization for a continuing survey to provide current statistical data on the amount, distribution, and effects of illness and disability in the United States. To fulfill the purposes of this act, it was recognized that data collection would involve at least three sources: (1) the people themselves by direct interview; (2) clinical tests, measurements, and physical examinations on sample persons; and (3) places where persons received medical care such as hospitals, clinics, and doctors’ offices. To comply with the 1956 act, the National Center for Health Statistics (NCHS) began the first National Health Examination Survey (NHES) in 1961. In the 1970s, Nutrition was added and NHES became the National Health and Nutrition Examination Survey (NHANES) that we have today.
The National Health and Nutrition Examination Survey is conducted by RTI International for the National Center for Health Statistics. http://www.rti.org.
NHANES covers things that aren’t usually done at routine check-ups. We will check to see if you have been exposed to harmful materials, like lead or mercury.
NHANES’ record of important accomplishments is made possible by the hundreds of thousands of Americans who have participated over the past 60 years. Participants in NHANES provide reliable population health data so healthcare personnel and policy makers can establish policies, and create research, education, and health promotion programs, making us all safer and healthier.
You may choose to be in the survey, and you may allow your child to be in it, too, if they are eligible. That is your choice. There is no penalty if you refuse any exam or decide not to answer any question. You are free to drop out at any time.