NHANES III is a multi-agency collaborative survey designed to estimate the prevalence of diseases and risk factors in some 30,000 Americans and conducted by the National Center for Health Statistics. Special efforts are being directed to collection of data from interviews and examinations for the population over age 60 and the oldest-old. Phase I of NHANES III, a national sample in itself and about one-half of the projected total, is completed. The overall examination rate is 78.7 percent and this rate is higher than for NHANES II. However, the response rates are somewhat lower for those 75 years and older. Home examinations are being done to improve the participation rate in older persons. Biomedical examination content of particular interest to EDB Program investigators includes 24-hour dietary recalls, bioelectrical impedance for body composition, bone density measurement, knee x-rays, and an assessment of physical functioning. Phase I data files are becoming available for preliminary use. Phase II of NHANES III data collection is continuing at the same time and early participation rates have been high.
