Survey of Non-Group Health Insurance Enrollees, Wave 2
The Kaiser Family Foundation (KFF) Survey of Non-Group Health Insurance Enrollees is the second in a series of surveys examining the views and experiences of people who purchase their own health insurance, including those whose coverage was purchased through a state or federal Health Insurance Marketplace and those who bought coverage outside the Marketplaces. The survey was designed and analyzed by researchers at KFF. Social Science Research Solutions (SSRS) collaborated with KFF researchers on sample design and weighting, and supervised the fieldwork. KFF paid for all costs associated with the survey.
The survey was conducted by telephone from February 18 through April 5, 2015 among a random sample of 804 adult U.S. residents who purchase their own insurance. Computer-assisted telephone interviews conducted by landline (346) and cell phone (458, including 241 who had no landline telephone) were carried out in English and Spanish by SSRS. Respondents were considered eligible for the survey if they met the following criteria:
- Between the ages of 18-64
- Currently covered by health insurance that they purchase themselves or purchased insurance that would begin in the next month
- Not covered by health insurance through an employer, COBRA, Medicare, Medicaid, a parent’s plan, or the U.S. military or VA
- If purchase insurance from a college or university, the insurance covers health services received both within and outside the university setting
- If a small business owner, the health insurance they purchase is only for themselves and/or their family, and does not cover non-related employees of their business
- If purchase from a trade association, respondent pays the entire premium themselves
Because the study targeted a low-incidence population, the sample was designed to increase efficiency in reaching this group, and consisted of three parts: (1) respondents reached through random digit dialing (RDD) landline and cell phone (N=151); (2) respondents reached by re-contacting those who indicated in a previous RDD survey that they either purchased their own insurance or were uninsured (N=247); (3) respondents reached as part of the SSRS Omnibus survey (N=406), a weekly, nationally representative RDD landline and cell phone survey. All RDD landline and cell phone samples were generated by Marketing Systems Group.
A multi-stage weighting process was applied to ensure an accurate representation of the national population of non-group enrollees ages 18-64. The first stage of weighting involved corrections for sample design, including accounting for the likelihood of non-response for the re-contact sample, number of eligible household members for those reached via landline, and a correction to account for the fact that respondents with both a landline and cell phone have a higher probability of selection. In the second weighting stage, demographic adjustments were applied to account for systematic non-response along known population parameters. No reliable administrative data were available for creating demographic weighting parameters for this group, since the most recent Census figures could not account for the changing demographics of non-group insurance enrollees brought about by the ACA. Therefore, demographic benchmarks were derived by compiling a sample of all respondents ages 18-64 interviewed on the SSRS Omnibus survey during the field period (N=6,519) and weighting this sample to match the national 18-64 year-old population based on the 2014 U.S. Census Current Population Survey March Supplement parameters for age, gender, education, race/ethnicity, region, population density, marital status, and phone use. This sample was then filtered to include respondents qualifying for the current survey, and the weighted demographics of this group were used as post-stratification weighting parameters for the standard RDD and omnibus samples (including gender, age, education, race/ethnicity, marital status, income, and population density). A final adjustment was made to the full sample to control for previous insurance status (estimated based on the combined RDD and omnibus samples), to address the possibility that the criteria used in selecting the prescreened sample could affect the estimates for previous insurance status.
Weighting adjustments had a minor impact on the overall demographic distribution of the sample, with the biggest adjustments being made based on age (this is common in all telephone surveys, as younger respondents are the most difficult to reach and convince to participate). Weighted and unweighted demographics of the final sample are shown in the table below.
|Unweighted% of total||Weighted% of total|
|Education||Less than high school graduate||6||7|
|High school graduate||26||31|
|Graduate school or more||13||9|
|Self-reported health status||Excellent||24||26|
All statistical tests of significance account for the effect of weighting. The margin of sampling error (MOSE) including the design effect is plus or minus 4 percentage points for results based on the total sample. Unweighted Ns and MOSE for key subgroups are shown in the table below. For other subgroups the margin of sampling error may be higher. Kaiser Family Foundation public opinion and survey research is a charter member of the Transparency Initiative of the American Association for Public Opinion Research.
|Total non-group enrollees||804||±4 percentage points|
|ACA-compliant plans||667||±5 percentage points|
|Marketplace plans||494||±6 percentage points|
|Non-ACA-compliant plans||127||±11 percentage points|