Codes and Frequencies
For 1989 forward, GLAUCOMAEV identifies adults who have ever been diagnosed with glaucoma. In 1989 and 1991, interviewers asked, "Has a doctor ever told you that you had glaucoma?" For 1999-forward, interviewers asked all sample adults, "Have you ever been told by a doctor or other health professional that you had glaucoma?"
In 1976, the question was broader in scope, demanding neither age restrictions nor professional diagnosis. Interviewers asked, "Has anyone in the family ever had ... glaucoma?"
The Field Representative's Manual defines glaucoma as "an increase in pressure in the eye which causes damage. If not treated soon enough, glaucoma can destroy side vision, leaving a small area in the center where the person still sees." This definition was not routinely shared with persons.
GLAUCOMAEV is completely comparable for 1999 forward. For other years, along with universe changes, changes in question wording limit comparability.
As evident in the question wording quoted in the description of the variable, diagnosis "by a doctor" was required in 1989 and 1991, while diagnosis by "a doctor or other health professional" was acceptable for 1999 forward. In 1989, the survey not only excluded "other health professionals" from the question wording but also reinforced the point, in the instructions to interviewers, that only doctors' diagnoses were acceptable. The 1989 Field Representative's Manual specifically directed interviewers to probe persons who indicated a diagnosis by a health professional other than a doctor, to determine if this other health professional was relaying the information from a medical doctor, and only then mark to "Yes."
The 1976 question poses the most serious challenges to comparability. In 1976, persons could answer for other family or household members, while self-reporting was required in later years. Proxy reporting yields less complete and accurate responses than self-reporting, at least when minor medical problems and brief contacts with health care professionals are the subject. Researchers should thus exercise particular caution when comparing results between 1976 and all later years.
- 1976: All persons.
- 1989: Persons age 18+ who have ever been told by a doctor that they had diabetes (other than during pregnancy).
- 1991: Sample persons age 18+.
- 1999; 2002; 2008; 2016 2017: Sample adults age 18+.
- 1976, 1989, 1991, 1999, 2002, 2008, 2016-2017