Codes and Frequencies
For sample adults and sample children, SSVISION indicates whether the person currently has a single health insurance plan for vision care. Prior to 2019, this variable was available for persons covered by a single service plan (SINGLEE).
Respondents were asked what type of single service plan they had and handed a list with different types of single service insurance coverage. Interviewers instructed them to mark all that applied. Beginning in 2019 all sample adults and sample children were asked if they were covered by a health insurance plan that only pays for vision services.
For 2004-2018, the survey included an additional probe question for all persons who indicated they were not covered by health insurance or did not indicate single service plan coverage. A person who responded to either HISINGLE or SSPROB, single service plan probe response, were asked about the type of service.
For variables indicating other types of single service variables, please see the SINGLEE variable description.
Users are also strongly encouraged to review the user note Insurance Data Collection.
SSVISION is mostly comparable, however the percent of respondents indicating single service coverage may increase for 2004 as a result of a probe question on whether the person had any single service plan.
However, it is not directly comparable with the variables for before 1997, such as values (e.g."06") in HI1SSTYP for 1993 to 1996. Beginning in 1997, the National Center for Health Statistics (NCHS) edited responses to what kind of insurance coverage respondents had based on plan name. Prior to 1997, individuals may have mistakenly reported having a single service plan but such errors were not edited for accuracy. In surveys before 1997, it is possible that not all individuals who indicated having a single service plan actually had such plans. This reduces comparability over time.
Starting in 2019 respondents were specifically asked if they had a plan that only pays for vision services rather than being asked to select the type of single service plan they had from a list.
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.
- 1999-2018: Persons covered by single service plan.
- 2019-2021: Sample adults age 18+ and sample children age 0-17.