Codes and Frequencies
Description
For sample adults and sample children (and, prior to 2019, all persons), HICHIP indicates whether the person had health insurance coverage under the Children's Health Insurance Program (CHIP). The Field Representative's Manual for 1999 defined CHIP as "a joint federal and state program, administered by each State that offers health care coverage to low-income, uninsured children. This law was passed in 1997." The Manual for 2001 forward added that the program is for children under age 19 who are not currently eligible for Medicaid or covered by private health insurance. CHIP programs have distinct names in many states. The state names for CHIP were listed on a flashcard shown to the respondent.
Data Editing and Recoding
HICHIP is not corrected for reporting errors. The NCHS strongly advises analysts to use recoded insurance variables as a more reliable source of information about the types of insurance coverage than is provided by respondents' original and unedited answers about their insurance type. The IPUMS NHIS provides the recoded insurance variable for HICHIP under HICHIPE.
During the course of data editing, the NCHS discovered many errors in the responses to questions about insurance coverage. Often, respondents misclassified the type of insurance they had. This might be shown, for example, by a mismatch between the verbatim name of an insurance plan and the type of insurance coverage the person selected from the categories on the card.
Accordingly, the NCHS created a series of recoded insurance variables. For these recoded insurance variables, the data are edited based on the verbatim names of insurance plans. HICHIP is not corrected for reporting errors. Analysis done by IHIS staff indicates that between 1999 to 2009, about 8 percent respondents either reported having CHIP but were found to be not covered by CHIP or reported they did not have CHIP but did have CHIP coverage, based on the plan name they provided.
Comparability
Other than the change in universe, this variable is largely comparable before 2019. Analysts may use HINOTCOV to restrict later samples to only persons with health insurance coverage and improve comparability with the 1999 sample. Substantial questionnaire changes introduced in 2019 may affect 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.
Universe
- 1999: Persons covered by some type of health plan.
- 2000-2018: All persons.
- 2019-2023: Sample adults age 18+ and sample children age 0-17.
Availability
- 1999-2023
Weights
- 1999-2018 : PERWEIGHT
- 2019-2023 : SAMPWEIGHT
