Codes and Frequencies
For sample adults who were ever told by a doctor or other health professional that they had diabetes (excluding pregnancy and prediabetes) (DIABETICEV), DIAYRSAGO reports the number of years since they were first diagnosed with diabetes.
DIAYRSAGO is a recoded variable calculated as the difference between current age (AGE) and reported age at the onset of diabetes (DIABETICAGE). The Codebooks for 1999 forward note, "For persons age 85 or older, this difference may be an underestimate" due to the fact that both AGE and DIABETICAGE are topcoded at age 85. Persons who had been diagnosed with "borderline diabetes" (in DIABETICEV) were not asked the follow-up question about age at onset of diabetes.
This variable is comparable between 2000 and 2018. Questionnaire changes introduced in 2019 affect comparability between 2019 and earlier years.
In 1999 only, if the difference between current age and reported age at onset of diagnosis of diabetes equaled "0" or "1," interviewers asked the follow-up question, "Was your diabetes diagnosed during the past 12 months?"(DIAGNOSYR) In 1999, this additional information was taken into account by the National Center for Health Statistics (NCHS) when distinguishing between the categories "Within past year" (IPUMS NHIS code 00) and "1 year" (IPUMS NHIS code 01) for DIAYRSAGO. In contrast, beginning in 2000, DIAYRSAGO was based entirely on the difference between reported current age and reported age at the onset of diabetes. Thus, beginning in 2000, for DIAYRSAGO, the Codebooks consistently noted, "Unlike in 1999, there is no follow-up question to determine onset in past year. For some with 1 year difference in age, onset will be within the past year."
There is a notable decline in the proportion of diabetics with past year onset of diabetes when comparing data from 1999 to data from 2000 and forward. This is probably due to the elimination of the follow-up question to determine past year onset from 2000 forward, resulting in the inability to distinguish onset within past year and onset 1 year ago for some respondents. To maximize comparability across all years, users should combine the categories "Within past year" and "1 year."
Questionnaire design changes introduced in 2019 limit comparability with earlier years. 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.
- 1976: Persons with some type of diabetes.
- 1989: Persons age 18+ who have ever been told by a doctor they had diabetes.
- 1999-2018: Sample adults age 18+ who were ever told they had diabetes (other than during pregnancy).
- 2019: Sample adults age 18+ who were ever told they had diabetes (excluding gestational diabetes and prediabetes).
- 1976, 1989, 1999-2019