The National Health Interview Survey [NHIS] is conducted by CDC’s National Center for Health Statistics.
NHIS is “the principal source of information on the health of the civilian non-institutionalized population of the United States”
The survey collects health and demographic data from a probability sample of approximately 43,000 households containing more than 100,000 people.
The survey has been fielded each year since 1957. Although the basic design of the survey has remained constant, it has evolved, enhancing its content and improving its design. The survey collects health and demographic information allowing analysts to examine health in terms of the characteristics of the population.
NCHS contracts with the Census Bureau to collect the data.
The current design includes:
A core set of questions,
A periodic set [which is repeated at intervals] and
A topical set which allows NCHS to collect data on topics of current interest.