The National Health Interview Survey is sponsored by the Department of Health and Human Services to obtain information about the amount and distribution of illnesses. The average monthly workload is 375 households, which are visited only once during the course of the survey. The survey include supplements on topics such as disability and AIDS.
The Census Bureau conducts the National Health Interview Survey for the National Center for Health Statistics to obtain national information about the amount and distribution of illness, its effects in terms of disability and chronic impairments, and the kind of health services people receive. The NHIS provides a continuing measure of the frequency of illnesses, injuries, and impairments in the population of the United States. In addition, the impacts of such conditions upon the population in terms of bed days, days lost from work, restricted activity, medical care received, and the number of hospitalizations experienced.