Codes and Frequencies
For sample adults, DIATESTLONG reports the length of time since they last had a blood test for high blood sugar or diabetes. Prior to 2019, DIATESTLONG was only asked of sample adults who do not have diabetes.
For 2016-2017, this variable was part of the Sample Adult Diabetes supplement, sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).
Because the intervals used to record respondents' answers varies over time, IPUMS NHIS uses a composite coding system for DIATESTLONG to maximize comparability.
The first digit identifies time periods which can be identified in all years: 1 year ago or less (code 1), 1 to 2 years (code 2), 2 to 3 years (code 3), 3+ years (code 4), Never (code 5), and unknown (code 9). The second digit specifies periods specified for only a subgroup of years.
However, users should be aware of how changes in the exclusive and inclusive nature of response categories impacts the comparability of the composite coding scheme. For example, in 2016 and 2017, all response categories are exclusive of the smaller year and inclusive of the larger year (i.e., "More than 1 year, but not more than 2 years ago"). However, beginning in 2019, all response categories are inclusive of the smaller year and exclusive of the larger year (i.e., "From 1 year to less than 2 yrs"). Therefore, someone who received a blood test exactly two years ago could be coded to "22 - More than 1 year, but not more than 2 years ago" in 2017, but could be coded to "32 - From 2 years to less than 3 yrs" in 2019. This is important if users choose to use only the first digit of the code, since someone who indicates it has been two years since their last blood test could be collapsed into the "2" category in 2017, but the "3" category in 2019. Users concerned about this level of detail may consider retaining all of the detailed codes instead of only looking at the first digit. Please see the codes tab for the availability of each response 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.
- 2016-2017: Sample adults 18+ who do not have diabetes.
- 2019-2020: Sample adults age 18+.
- 2016-2017, 2019-2020
- 2016-2017, 2019-2020 : SAMPWEIGHT