The second National Health and Nutrition Examination Survey (NHANES II) is one of a series of related programs carried out over the past 20 years by the U. S. National Center for Health Statistics. The first National Health and Nutrition Examination Survey (NHANES I, DAAPPP data set 19) was designed as a national probability study involving approximately 30,000 individuals and was carried out between 1971 and 1975. Even before the completion of NHANES I, plans were underway for the second survey. A major consideration in the design of the NHANES II was that content and procedures should permit comparison with NHANES I data. The experience gained in the NHANES I program, however, made possible certain modifications in NHANES II in order to make the data obtained more useful. For example, NHANES I revealed anemia to be a significant health problem in the U.S., and anemia was investigated in more detail in NHANES II. Additional variables were also included in the study after extensive consultation with numerous other Federal agencies and departments.

The survey included two main components: (1) household and medical history questionnaires, and (2) medical examinations. The questionnaires were designed to obtain basic demographic data, information on participation in food programs, and data on each individual's general medical history. The medical examination included dental, dermatological, and ophthalmological examinations; body measurements; biochemical tests; a supplementary medical history questionnaire; and dietary interviews. Like the NHANES I file, the NHANES II DAAPPP file contains information on demographic background characteristics; participation in school lunch, milk, and breakfast programs; birth weight and condition; medical history; and medical examination results, including indices of nutritional status, body build, and bone structure.

The DAAPPP HANES II file contains data only for children aged 6 months to 11 years. Because data on the age of the child's mother is included, this is an excellent data set for examining the health consequences for children of teen-aged mothers.