For about half a century, people in the United States have been asked the same questions: How old are you? What do you and your family eat? Does anyone smoke? How much alcohol do you drink? How's your health?
And when all those answers are gathered, the Centers for Disease Control and Prevention issues an annual report -- the National Health and Nutrition Examination Survey. The data contained tells local doctors what's happening throughout the country with a host of diseases -- cancer, heart disease, high blood pressure, diabetes -- and the health conditions that contribute to them, such as obesity and environmental exposures.
The CDC's most recent National Health and Nutrition Examination Survey encompasses information gathered in 2011-12.
"It's the backbone of what I do,'' said Dr. Madhu Mathur, a pediatrician and public health specialist at Stamford Hospital, who is now helping to design community programs to reduce obesity rates in the city.
"It's a very important and helpful tool,'' said Dr. Thomas Draper, the longtime public health adviser to the city of Danbury.
Starting Monday, the CDC will ask about 900 people in Fairfield County to be part of this survey. If they consent, the information the CDC gathers -- through interviews and physical examinations -- will be used in a future CDC report.
Tatiana Nwankwo, a public health adviser at the CDC's National Center for Health Statistics in Hyattsville, Md., said in all, about 5,000 people spread among 15 counties around the country participate in the survey each year, with the people and counties changing annually. This year, she said, it's Fairfield County's turn to participate.
Nwankwo said the CDC uses census data to get an accurate cross-section of Americans to participate in the study, in terms of age, gender, ethnicity and income.
"It's a snapshot each year of the nation's health,'' she said.
Nwankwo said people asked to participate in the survey will first receive a letter, asking them to join the study. They'll each get $125 -- and the satisfaction of helping the CDC -- for their efforts.
If they do join, a CDC staff member will arrive at their homes for an interview that can last from a hour to 90 minutes, depending on the number of people in the household and their general health.
"Older people can take a little longer,'' she said.
About 340 people will then go to a CDC mobile clinic, where they'll each get a state-of-the-art physical exam. The CDC will give the results of the physicals to the participants, so that they can share the information with their doctors.
But Nwankwo said the reports completely protect the participants' confidentiality. The CDC never mentions the towns, or even the counties, where it gathers the information. It combines the data from the 5,000 people into a two-year report, involving 10,000 people, all the data is combined into a single report representing the entire country.
"We've never had a breach of confidentiality,'' Nwankwo said.
But although not specifically about any one place, the report is of great value to people studying public health issues.
Sally Herlihy, vice president of planning at Western Connecticut Health Network -- which includes Danbury and New Milford hospitals -- said when the hospital and other organizations wrote their Community Report Card in 2009, the survey's data provided them with a starting point.
"It's some of the information we used as we pulled together a picture of the community,'' Herlihy said.
Lyn Salsgiver, Bridgeport Hospital's senior vice president for planning and marketing, said the data in the survey, gives hospitals and the staff of public health departments an idea of important health trends in the United States.
"We can do more screening, more health education,'' she said.
Mathur gave this example of the value of the survey: With it, she said, health officials learned that obesity rates are rising nationally in 2-to-5-year-olds.
"That means it's not a school issue, not kids getting too much soda outside of home,'' Mathur said. "It means the problem is in the home. We can design community programs to try and help change that.''