Abstract
The National Health and Nutrition Examination Survey (NHANES), developed by the Centers for Disease Control and Prevention, is a large and comprehensive health survey utilizing leading edge technologies to produce national estimates of health measures and the nutritional status of the United States population. Continuous quality assurance (QA) and quality control (QC) are the basic components to insure NHANES delivers high quality timely data. The QA activities before data collection consist of equipment calibration and training, while the QC activities during collection consist of automated software edits, data analysis of technician performance and analytic processing. These activities are tightly coupled in a continuous two-phase process through the data collection cycle, eventually leading to data release.