Codes and Frequencies
For sample adults (and, prior to 2019, for all persons aged 5 and older), EDUC reports the highest level of schooling an individual had completed, in terms of completed grades for persons with less than a high school degree, and in terms of degrees attained for high school graduates and those with higher education. Respondents were handed a card listing recognized categories and asked to identify the correct category.
According to the Field Representative's Manuals for 1997-2000, only "regular schooling which advances a person toward an elementary or high school diploma, or a college/university/professional school (such as law, medicine, dentistry)" counted as education. Schooling in settings other than "regular schools" counted only if the credits obtained were acceptable in a regular school system. Thus, for example, "adult education" classes not taken for credit or for the attainment of a college degree did not count.
For the end of high school, EDUC distinguishes between those who completed twelfth grade but did not attain a diploma (e.g., those who failed to pass state-mandated high school exit examinations), those who graduated from high school, and those passed the GED (General Equivalence Degree) Test (which certifies that the test taker has attained high school-level academic skills). Persons who attained a high school diploma in less than twelve years were to be recorded as "high school graduates," a guideline consistent with EDUC's emphasis on degrees attained rather than years spent in the classroom. The Field Representative's Manual for 1997-2000 directed interviewers to probe to determine whether persons who attended "post-graduate" high school classes but did not attend college had received a high school diploma.
For nurses, interviewers were to determine whether training was received in a college or in a nursing school (with the grade completed at the last regular--non-nursing--school to be entered in the latter case). For a person attending special education classes or a school for persons with mental, physical, or developmental difficulties, interviewers were to ask which grade in a regular school most closely matched the individual's education level. Persons currently in school were generally assumed to have completed the previous grade.
There are several changes in the universe and coding of EDUC that may affect comparability.
In 2021, the categories of Professional Degree and Doctoral Degree were collapsed together to preserve confidentiality.
Beginning in 2019, there were substantial changes in both the universe and coding for levels of education below a high school diploma or equivalent. In 2019, the universe changed from all persons aged 5 and older to sample adults age 18 and older, which also has implications for the appropriate sampling weight to use in analyses including EDUC. Also in 2019, grade levels 1 through 11 were collapsed into a single category, rather than each grade level being assigned its own category. 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.
Prior to 2003, consistency checks between age and years of education were performed for persons aged 5-17. Beginning in 2004, original NCHS documentation notes this was a minimal consistency check.
Prior to 1997, information on educational attainment was collected in terms of years of schooling, rather than degrees attained. EDUCREC1 (Educational attainment recode, nonintervalled) provides a bridge for schooling information collected before and after 1997, by recoding data on years of schooling into the equivalent categories for degrees attained.
- 1997-2018: Persons age 5+.
- 2019-2021: Sample adults age 18+.
- 1997-2018 : PERWEIGHT
- 2019-2021 : SAMPWEIGHT