Codes and Frequencies
CEREBPALEV reports whether the person has cerebral palsy. Due to an interviewer error, NHIS suggests not using this variable for analysis from 2004 to 2007 Quarter 2. Please see Comparability and Universe tabs for changes in universe and question wording between samples.
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.
The Field Representative's Manual for 2001 forward defined Cerebral Palsy as "a disability resulting from damage to the brain before, during, or shortly after birth and outwardly manifested by muscular in coordination and speech disturbances." This definition was not routinely shared with respondents.
From 1997 forward, cerebral palsy was also included in the survey as an example of "other developmental problem" (i.e., "other" relative to "mental retardation") when information was collected on the conditions or health problems that limited an individual's activities (CLIMOTHDEV). Information was collected separately on whether a sample child was ever diagnosed as having "other developmental delay" (i.e., "other" relative to "Mental Retardation" and "ADD/ADHD") (ODDEV).
Changes in universe and question wording affect comparability between samples.
In 1988, the household respondent was asked if the sample child, age under 18, has ever had cerebral palsy.
In 1994 and 1995, this question refers to all persons in the National Health Interview Survey-Disability Survey (NHIS-D) Phase I sample. In those years, this question reports whether the person has cerebral palsy.
For 1997 forward, the household respondent was asked whether "a doctor or other health professional ever told you that" the sample person had cerebral palsy. In 2008, the universe includes sample children and sample adults; in all other years from 1997 on the universe includes only sample children under age 18.
Beginning in 2006, the "Notes" section of the sample child layout codebook reported a problem in the frequencies for this variable from 2004 to Quarter 2 of 2007. For example, the 2009 codebook contained the following text:
Based on the frequency distribution for the CEREBPALEV variable in the NHIS public use files, this error is no longer present in the data for 2008 and later years. Researchers are recommended not to use this variable for 2004-2007 Quarter 2 (the problematic period).
- 1988: Sample children under age 18.
- 1994-1995: Persons in the NHIS-D Phase I sample.
- 1997-2007: Sample children under age 18.
- 2008: All sample persons.
- 2009-2018: Sample children under age 18.
- 1988, 1994-1995, 1997-2018