COSTA MESA, Calif. — Orange County has been selected to participate in a health survey that county officials say will help provide data on preventing illness, not just treating symptoms. 

The survey, conducted by the National Health and Nutrition Examination Survey, will be advertised to residents by mail, encouraging people to answer a series of questions online. Eligible respondents will then be scheduled for a telephone screening and in-person evaluation.

“If you’re healthy, we want to know why you’re healthy,” said Dr. Tony Nguyen, chief medical officer of NHANES.

NHANES tracks the health and nutrition of populations using data from surveys and physicals. As part of the Centers for Disease Control and Prevention, NHANES provides national health statistics that appear in doctor’s offices nationwide.

At more than 60 years old, the program pulls a representative cross-section from about 15 counties nationwide each year. The survey drills down into demographic, socioeconomic and dietary questions.

“This is the quintessential diverse community,” said Vicente Sarmiento, Orange County second district supervisor. “In essence, it is the microcosm of our nation.”

The mobile exam center comprises four trailers that connect to create one large screening station. Each patient receives a bracelet with a barcode and gown for the examination. The examination includes screening for heavy metals, urine and blood tests, a liver test with an ultrasound machine and even a balance test depending on the patient’s age to better understand their risk of falling. The exam will also look at muscle mass and other body composition factors, which can be used to help understand the health of the population.

For children, the exam will cover height and weight, which help establish the growth charts used in doctors’ offices. Patients can expect results by mail about two weeks later.

The goal is to get a better understanding of health markers that may never be assessed during a typical visit to a primary care doctor.

“It really helps us understand things we don’t normally diagnose in a doctor’s office,” said Dr. Regina Chinsio-Kwong, county health officer for the Orange County Health Care Agency.