NHANES

Questions and Answers Facts

  • What is the National Health and Nutrition Examination Survey (NHANES)?
You, or a member of your family, may have a chance to take part in an important national health survey. The National Center for Health Statistics, a part of the Centers for Disease Control and Prevention, is responsible for this survey - The National Health and Nutrition Examination Survey (NHANES). This survey teaches us about the health and diet of people in the United States. Over the years, this survey has led to improvements in the food we eat and the health care we receive. 

  • How was I selected?
Participants are selected through a complex statistical process using the most current Census information. In simple terms, NHANES divides the United States into counties. Fifteen counties are selected across the U.S. each year. The counties are divided into neighborhoods. The neighborhoods are selected at random. From each neighborhood, housing units are selected at random. You may have received our introductory letter or a postcard, sent to "resident" at your home address. Please be on the lookout for these letters or postcards the last week of August.

Selected households are approached by our interviewers who ask a few short questions to determine if anyone in the household is eligible for the study.


  • Why was I selected?
You have a unique health profile; if you are selected to be a participant, no other person can be substituted for you. You were selected based on your age, gender, and racial/ethnic background. No one can take your place in this survey. Each person represents approximately 65,000 other U.S. residents. The identities of all participants are held strictly confidential. 

  • Who participates?
Approximately 5,000 individuals will be examined each year across the United States. 

  • How do I know this is a legitimate survey?
NHANES has a long history; it has been in existence since the early 1960s and has surveyed over 250,000 people. Past Participants have gained new insight into their health and have enjoyed taking part in the survey. The feedback we have received from participants includes:

• "My daughter and I went through the survey and exam and we were both glad we did it. Everyone was so nice."
• "I was impressed by how professional everyone was."
• "I think it is great that the government helps keep us informed about health issues."
• "I was impressed by all of the high tech equipment."

Additionally, many national organizations and Universities have endorsed NHANES through letters of endorsement.

The NHANES staff consists of professional individuals with a variety of health, research, and academic backgrounds. The staff in the mobile examination center includes a doctor, a phlebotomist, health technicians and highly trained interviewers.

  • Is my information confidential?
Public laws keep all information participants give confidential. We will hold all data we collect in the strictest confidence. Federal laws prohibit us from giving out information that identifies you or your family without your consent. This means that we cannot give out any fact about you, even if a court of law asks for it. We will keep all survey data safe and secure. We assign code numbers in place of names or other facts that could identify you. 

  • What is involved in Participating?
There are three main parts to this survey: the doorstep screener, the home interview and the health examination. 

The doorstep Screener (takes about 5 minutes to complete)
-An NHANES interviewer will come to your home to talk to you about the survey. This interviewer should present an identification badge, which identifies this person as a health representative working on the National Health and Nutrition Examination Survey. The interviewer will then ask you a few questions to see if you qualify to participate.

The Interview (takes about 1 hour to complete but can be longer for non- English speakers)
-If you do, the interviewer will set up an appointment with you for an in-home interview. During this interview, you will be asked questions about your health, disease history, and diet.

Again, anything you say during this interview is confidential.

The Health Examination (takes about 1-4 hours to complete, the exam depends on your age and gender)
-The Mobile Exam Center (MEC) contains high-tech medical equipment. The MEC is situated in a location convenient for participants. The NHANES staff can help you with transportation to the MEC if needed. You will have a health examination consisting of a number of measurements and tests. The exams will depend on your age, gender, and current medical conditions.

**This exam is not a substitute for your regular health care examination. There will be no invasive internal exam and no drug testing.

  • What are the Benefits of Participating?
-Many of the measurements and tests performed in the Mobile Exam Center are unique, and they are not commonly done in doctor's offices during routine physical exams. This is a chance for you to gain additional health information about yourself and your family’s health. These tests are done at no expense to you.

-Every participant will receive results from their examination. Participants will receive a preliminary report of findings when they leave the mobile exam center and a complete report of their results will be mailed to participants 12-16 weeks after the exam. These results are yours to discuss with your doctor or keep for your own medical records.

-Contributing to the Health Knowledge of the U.S.

-NHANES has traditionally published findings on a range of topics often through the news media. Topics include obesity, cholesterol, hypertension, blood lead levels, growth charts, osteoporosis and dietary intake.

-All participants, regardless of age, are given a cash payment as a "thank-you" for their time and effort. NHANES will also reimburse participants for transportation and baby/elder care.

  • Is there a local representative?
Yes, George Dixon is the study manager, our local representative in Wichita County. If you have questions, he can be reached at 800.210.3413 

  • How long will the survey be in town?
NHANES will be in town September 21 through November 19, 2018. 

  • Do I have to speak English to participate?
No, we accommodate everyone who is eligible to participate in the survey. Our interviewers use a language identification card to identify the language spoken in a given household. Once that language is identified, we use interpreters to conduct the survey. 


For more information, please call 1-800-452-6115 or visit www.cdc.gov/nhanes