Country: United States
Survey Organization: SSRS
Field Dates: November 2–December 27, 2017
Sample: Nationally representative sample of 2,410 adults, ages 19 to 64
Sample Size: Overall, 122 interviews were conducted on landline telephones and 2,288 interviews on cellular phones.
How We Conducted This Survey
The most recent Commonwealth Fund Affordable Care Act Tracking Survey was conducted by SSRS from November 2 to December 27, 2017. The survey consisted of telephone interviews in English or Spanish and was conducted among a random, nationally representative sample of 2,410 adults, ages 19 to 64, living in the United States. Overall, 122 interviews were conducted on landline telephones and 2,288 interviews on cell phones.
This survey is the sixth in a series of Commonwealth Fund surveys to track the implementation and impact of the ACA. The first was conducted by SSRS from July 15 to September 8, 2013, by telephone among a random, nationally representative U.S. sample of 6,132 adults ages 19 to 64. The survey had an overall margin of sampling error of +/– 1.8 percent at the 95 percent confidence level.
The second survey in the series was conducted by SSRS from April 9 to June 2, 2014, by telephone among a random, nationally representative U.S. sample of 4,425 adults ages 19 to 64. The survey had an overall margin of sampling error of +/– 2.1 percent at the 95 percent confidence level. The sample for the April–June 2014 survey was designed to increase the likelihood of surveying respondents who were most likely eligible for new coverage options under the ACA. As such, respondents in the July–September 2013 survey who said they were uninsured or had individual coverage were asked if they could be recontacted for the April–June 2014 survey. SSRS also recontacted households reached through their omnibus survey of adults who were uninsured or had individual coverage prior to the first open enrollment period for 2014 marketplace coverage.
The third survey in the series was conducted by SSRS from March 9 to May 3, 2015, by telephone among a random, nationally representative U.S. sample of 4,881 adults, ages 19 to 64. The March–May 2015 sample was also designed to increase the likelihood of surveying respondents who had gained coverage under the ACA. SSRS recontacted households reached through their omnibus survey of adults between November 5, 2014, and February 1, 2015, who were uninsured, had individual coverage, had a marketplace plan, or had public insurance. The survey had an overall margin of sampling error of +/– 2.1 percentage points at the 95 percent confidence level.
The fourth survey in the series was conducted by SSRS from February 2 to April 5, 2016, by telephone among a random, nationally representative U.S. sample of 4,802 adults, ages 19 to 64. The February–April 2016 sample was also designed to increase the likelihood of surveying respondents who had gained coverage under the ACA. Interviews in wave 4 were obtained through two sources: 1) stratified RDD sample, using the same methodology as in waves 1–3; and 2) households reached through the SSRS Omnibus, where interviews were previously completed with respondents ages 19 to 64 who were uninsured, had individual coverage, had a marketplace plan, or had public insurance. The survey had an overall margin of sampling error of +/– 2.0 percentage points at the 95 percent confidence level.
The fifth survey in the series was conducted by SSRS from March 28 to June 20, 2017, by telephone among a random, nationally representative U.S. sample of 4,813 adults, ages 19 to 64. The March–June 2017 sample was also designed to increase the likelihood of surveying respondents who had gained coverage under the ACA. Interviews in wave 5 were obtained through two sources: 1) stratified RDD sample, using the same methodology as in waves 1–4; and 2) households reached through the SSRS Omnibus where interviews were previously completed with respondents ages 19 to 64 who were uninsured, had individual coverage, had a marketplace plan, or had public insurance. The survey had an overall margin of sampling error of +/– 1.8 percentage points at the 95 percent confidence level.
The November–December 2017 sample was also designed to increase the likelihood of surveying respondents who had gained coverage under the ACA. Interviews in wave 6 were obtained through two sources: 1) stratified RDD sample, using the same methodology as in waves 1–5; and 2) households reached through the SSRS Omnibus, where interviews were previously completed with respondents ages 19 to 64 who were uninsured, had individual coverage, had a marketplace plan, or had public insurance.
As in all waves of the survey, SSRS oversampled adults with incomes under 250 percent of the federal poverty level to further increase the likelihood of surveying respondents eligible for the coverage options as well as to allow separate analyses of responses from low-income households.
The data were weighted to correct for oversampling uninsured and direct purchase respondents, the stratified sample design, the overlapping landline and cell phone sample frames, and disproportionate nonresponse that might bias results. New to this wave’s sample design, the weights also corrected for oversampling respondents with a prepaid cell phone. The data are weighted to the U.S. 19-to-64 adult population by age by state, gender by state, race/ethnicity by state, education by state, household size, geographic division, and population density using the U.S. Census Bureau’s 2015 American Community Survey. Data were weighted to household telephone use parameters based on the CDC’s 2016 National Health Interview Survey (NHIS).
The resulting weighted sample is representative of the approximately 190 million U.S. adults ages 19 to 64. Data for income, and subsequently for federal poverty level, were imputed for cases with missing data, utilizing a standard general linear model procedure. The survey has an overall margin of sampling error of +/– 2.7 percentage points at the 95 percent confidence level. The overall response rate, including the prescreened sample, was
7.0 percent
.
