Codes and Frequencies
RETEV reports whether the person has an intellectual disability, also known as mental retardation. Please see Comparability and Universe tabs for changes in universe and question wording between samples.
The Field Representative's Manual states, "Mental Retardation refers to someone who is significantly below average in intellectual functioning, in addition to having problems with adaptive behavior." This official definition was not routinely quoted as part of the interview process and presumably would have been cited only if a subject asked for clarification.
In 1994 and 1995, this variable is part of the Disability Supplement (NHIS-D) that collects information on disability. NHIS-D included two household interviews: in Phase I all members of sample families were screened for any indication of disability; in Phase II persons with any indication of disability were followed-up for additional information. Phase I includes sensory, communication, and mobility problems; health conditions; activities of daily living and independent activities of daily living; functional limitations; mental health; services and benefits; special health needs of children; early child development; education; relationship to respondent; and perceived disability. Phase II includes four Disability Followback Survey (DFS) questionnaires: one for children, one for adults, one for elderly persons (69 years of age and over) without any indication of disability (also called the Supplement on Aging or SOA; only in 1994), and one for persons with a history of polio.
Information was collected separately on ADD/ADHD (Attention Deficit Disorder/Attention Deficit Hyperactive Disorder) (ADDEV) for sample children aged 2 to 17 and on "Other Developmental Delay" (ODDEV) for all sample children. In another question, information was collected on one of the main causes of mental retardation, Down Syndrome (DOWNSYNEV).
Mental retardation was also incorporated into the survey as one of the possible conditions or health problems that respondents could select from a list on a flash card, to explain why individuals were limited in their activities.
Changes in universe and question wording affect comparability between samples.
In 1994 and 1995, all persons in the National Health Interview Survey-Disability Survey (NHIS-D) Phase I sample are included in the universe. In those years, the household respondent was asked to identify any persons in the family who have mental retardation.
From 1997 on, this question was asked only of sample children under age 18. From 1997 to 2010, the household respondent was asked if he or she had ever been told by a doctor or health professional that the sample child had mental retardation. Beginning in 2011, the phrase "mental retardation" was replaced with the phrase "intellectual disability, also known as mental retardation" in the survey question associated with RETEV. Apart from this change in wording, the variable is fully comparable from 1997 on.
The NHIS questionnaire was substantially redesigned in 2019 to introduce a different data collection structure and new content. For more information on changes in terminology, universes, and data collection methods beginning in 2019, please see the user note.
- 1994-1995: Persons in the NHIS-D Phase I sample.
- 1997-2018: Sample children age 0-17.
- 2019-2021: Sample children age 0-17.
- 1994-1995, 1997-2021