How is NHANES Data Collected?
When NHES was originally conceived, it was determined that data would come from three primary sources: • Direct Interview: directly interviewing the survey participant and those within their household about their health. • Direct Examination: conducting clinical tests, anthropometric , biochemical , and radiological measurements, and physical examinations. • Physician Inquiry/Medical Records: reviewing participant’s medical record. In current practice, however, NHANES data are derived primarily from the first two sources; that is, via direct interview and direct clinical examination. The NHANES data collection procedures have changed slightly over the years. These changes reflect not only the changing demographics of the United States over time, but also the changing nature of the survey (e.g., the inclusion of the nutrition component, the interest in the effects of environment upon health). Nonetheless, the basic tenets of data collection, particularly with regards to sampling, are si
