Does the health and nutritional status of Americans change over time?

Challenge

The National Health and Nutrition Examination Survey (NHANES) assesses the health and nutritional status of adults and children in the U.S. The NHANES interview includes demographic, dietary, and health-related questions. The examination component consists of medical, dental, and physiological measurements, as well as laboratory tests administered by highly trained medical personnel. Westat conducted this study since the early 1980s, including the Hispanic HANES and NHANES III and IV.

Solution

For the National Center for Health Statistics (NCHS), Westat conducted NHANES through interviews and extensive physical examinations performed in specially equipped mobile examination centers (MECs) that traveled from site to site.

NHANES is a continuous survey with year-round data collection; each year our field staff were dispatched to 15 counties across the country to conduct interviews and extensive physical examinations with approximately 5,000 Americans of all ages.

We employed approximately 80 full-time traveling staff to conduct the study, including 2 medical teams and a group of household interviewers managed by home-based supervisors. An experienced team of research and IT professionals supervised the advance arrangements for data collection, monitored the progress and quality of data collection, and prepared and processed all survey data.

An integrated survey information system supported all aspects of sampling, data collection, survey monitoring, and data management. This system operated across a wide area network that provided near real-time communication between the examination centers, NCHS, and Westat.

This study used Blaise, a comprehensive commercial off-the-shelf (COTS) survey processing system. It provides integrated multimode support for computer-assisted survey data collection.

Results

The findings from NHANES help determine the prevalence of major diseases and risk factors for diseases.

They also help to develop sound public health policy, direct and design health programs and services, and expand the health knowledge for the nation.