Technical Notes: Data and Methods ASPE Health Insurance Coverage Fact Sheet, September 2015

09/22/2015

Survey Data:

  1.  Estimate of impact of dependent coverage provision, measuring the change in young adult insurance coverage, 2010-2013

We generally prefer to use the National Health Interview Survey (NHIS) for our health insurance coverage estimates because it is a large national survey with robust sampling methods.  In March 2015, we were able to use NHIS data through the third quarter of 2013 to update our estimate of the impact of the Affordable Care Act (ACA) dependent coverage provision, which allowed young adults aged 19-25 to stay on their parent’s health insurance policy starting in September 2010.  

 

  1.  Estimate of change in health insurance coverage for 18-64 population, Q3 2013-Q3 2015

To estimate the impact of the ACA health insurance coverage expansion through the Health Insurance Marketplaces and Medicaid, we cannot use the NHIS because data for the third quarter of 2015 is not yet available.  Therefore, we use the most recent data available on health insurance coverage from the Gallup-Healthways Well-Being Index Survey, which are collected daily and become available soon after data collection. The data in this brief reflect interviews through September 12, 2015.  Analyses to date suggest the Gallup-Healthways Well-Being Index survey’s national uninsured estimates track the NHIS national estimates quite closely (see http://aspe.hhs.gov/health/reports/2014/InsuranceEstimates/ib_InsuranceEstimates.pdf).   (There is a review of a number of nonfederal surveys from the Urban Institute at:   http://www.urban.org/UploadedPDF/2000146-Nonfederal-Surveys-Fill-a-Gap-in-Data-on-ACA.pdf).

 

Therefore, for the purpose of near real-time national health insurance coverage tracking, Gallup-Healthways Well-Being Index survey offers a timely interim solution between NHIS reporting periods.

 

Methods:

  1.  Estimate of impact of dependent coverage provision, measuring the change in young adult insurance coverage, 2010-2013

 

In March 2015, we used NHIS data to update our earlier estimates of the impact of the young adult dependent coverage provision of the ACA that took effect in September 2010.[1] In this current brief, we use the same estimate of the impact of the dependent coverage provision as we reported in March.[2]  We used a baseline period stretching from Q4 2009 through Q3 2010 and compared it to the post period defined as Q4 2012 through Q3 2013.  Because we had more data available in March, we updated our estimate published in June 2012 (which used a single quarter of data), using longer pre and post periods in order to smooth away random variation in the uninsured rate. This reduces the influence of random variation in the estimates of the number of uninsured on the exact start and end dates for the analysis, but could allow either more or less opportunity for confounding from other factors.  Our estimate showed an additional 2.3 million young adults gaining coverage. We also performed a sensitivity analysis in which we smoothed only the post period and used Q3 2010 as the baseline, yielding an estimate of 2.8 million additional insured young adults. Thus our core estimate, 2.3 million, is more conservative. We note that individuals move into and out of the 19-25 young adult cohort as they age, so the 2.3 million is an estimate of the increased prevalence in coverage at a specific point in time.  It is not a longitudinal estimate of all individuals who may have benefited from the provision at any point in time since 2010, which would be considerably larger.

 

ASPE Brief date

Young adult increase in insurance coverage estimate

Baseline period

End period

June 2012

3.1 million

Q3 2010

Q4 2011

March 2015

2.3 million

Q4 2009 – Q3 2010

Q4 2012 – Q3 2013

March 2015 Sensitivity Analysis

2.8 million

Q3 2010

Q4 2012 – Q3 2013

 

  1.  Estimate of change in health insurance coverage for 18-64 population, Q3 2013-Q3 2015

We used the Gallup-Healthways Well-Being Index to estimate the change in the national uninsured rate from the baseline period of Q1 2012-Q3 2013 to a final period of July 1, 2015 through September 12, 2015. The 2015 Health Insurance Marketplace open enrollment season ended on February 15th with a Special Enrollment Period extending through February 22nd in many states.  The Special Enrollment Period for tax season began on March 15th and concluded on April 30th.

 

We determined the change in uninsured rates for the nation, states with and without the Medicaid expansion, and persons with different demographic characteristics. We computed these uninsured rates by updating the methodology used in the ASPE issue brief “Health Insurance Coverage and the Affordable Care Act”, published in March 2015, which adjusted for demographic and economic covariates: age, race, household income, ethnic group, sex, employment status, and state of residence.  The current methodology also adjusts for marital status and rural residence.  These covarietes are aimed to control for changes in the economy, population composition, and non-policy factors affecting health insurance coverage.  This methodology does not adjust for household income because on June 1, 2015, Gallup changed the wording of its questionnaire to collect respondents’ annual income instead of monthly income.  Historical estimates have been updated to reflect these changes in methodology and differ from those in ASPE’s analysis from March 2015 (http://aspe.hhs.gov/health-insurance-coverage-and-affordable-care-act-aspe-issue-brief-march-2015).  The table below compares overall estimates of the uninsured that we reported in March to estimates of the uninsured using the current methodology.  It is worth noting that the Q1 2015 estimate we reported in March did not reflect a full period of data (the March report used data through March 4th) and, even under the March methodology, would have changed once the full quarter of data was available.

 

Period

Previous Estimate

Current Estimate

Q1 2014

5.2 million (17.7% uninsured rate)

4.3 million (18.1% uninsured rate)

Q3 2014

10.7 million (14.9% uninsured rate)

11.5 million (15.1% uninsured rate)

Q1 2015

14.1 million (13.2% uninsured rate)

14.3 million (13.1% uninsured rate)

 

The brief includes adults aged 18-64. We excluded adults 65 years of age or older from this brief because a very high proportion are already enrolled in Medicare and thus not eligible for the coverage expansion under the ACA. Gallup-Healthways does not collect data on the 17 and under population.

 

For the national, race/ethnicity, young adult, and gender analyses, we used 2015 Census population projections to obtain population estimates for each subgroup. The population estimates we used are as follows:

 

Subgroups

2015 Census Population Projection

National (18-64 years)

199.9 million

White Non-Hispanic (18-64 years)

123.0 million

African-American Non-Hispanic (18-64 years)

25.5 million

Latino (18-64 years)

34.9 million

Young adults (19-25 years)

31.7 million

Males (18-64 years)

99.6 million

Females (18-64 years)

100.3 million

 

For purposes of this brief, ASPE only analyzed gains in health coverage among White Non-Hispanics, African-American Non-Hispanics, and Latinos.   Numbers do not add to 15.3 million because “other races” are not included in the table.  More detailed results with confidence intervals are below:

 

 

 

Baseline Uninsured Rate

Q1 2014

Q3 2014

Q1 2015

Q2 2015

Q3 2015

Change in Percentage Points from Baseline Trend (95% CI)

White

14.3

-1.5 (-2.3, -.08)

-4.8 (-5.7, -3.9)

-5.7 (-6.8, -4.7)

-6.2 (-7.3, -5.0)

-6.0 (-7.2, -4.8)

African-American

22.4

-3.8 (-6.3, -1.4)

-6.6 (-9.4, -3.8)

-9.8 (-13.0, -6.5)

-11.3 (-14.8, -7.8)

-10.3 (-14.2, -6.5)

Latino

41.8

-3.4 (-6.0, -.09)

-5.4 (-8.3, -2.5)

-10.5 (-13.8, -7.1)

-11.5 (-15.1, -7.9)

-11.5 (-15.5, -7.6)

 

 

We counted states as having expanded their Medicaid programs if they had done so as of July 1, 2015. This includes AZ, AR, CA, CO, CT, DE, DC, HI, IL, IN, IA, KY, MD, MA, MI, MN, NV, NH, NJ, NM, NY, ND, OH, OR, PA, RI, VT, WA, and WV.  AK began its expansion on September 1, 2015 and is not included as an expansion state in this analysis.  More detailed results with confidence intervals are below:

 

 

 

 

 

Baseline Uninsured Rate

Q1 2014

Q3 2014

Q1 2015

Q2 2015

Q3 2015

Change in Percentage Points from Baseline Trend (95% CI)

Non-expansion

23.4

-2.0 (-3.2, -.07)

-4.2 (-5.6, -2.8)

-7.0 (-8.6, -5.3)

-6.9 (-8.7, -5.2)

-7.3 (-9.2, - 5.4)

Expansion

18.2

-2.5 (-3.4, -1.5)

-6.0 (-7.1, -5.0)

-7.5 (-8.7, -6.3)

-8.8 (-10.1, -7.5)

-8.1 (-9.5, -6.7)

 

 

We analyzed how many young adults (aged 19-25) are part of the 15.8 million adults who have gained coverage since the baseline period of Q1 2012-Q3 2013. More detailed results with confidence intervals are below:

 

Baseline Uninsured Rate

Q1 2014

Q3 2014

Q1 2015

Q2 2015

Q3 2015

Change in Percentage Points from Baseline Trend (95% CI)

Young Adults

26.0

-2.6 (-4.9, -.03)

-6.5 (-9.0, -4.0)

-9.1 (-12.0, -6.1)

-10.1 (-13.2, -6.9)

-10.1 (-13.5, -6.7)

 

We analyzed gains in health coverage by gender. More detailed results with confidence intervals are below:

 

 

 

 

Baseline Uninsured Rate

Q1 2014

Q3 2014

Q1 2015

Q2 2015

Q3 2015

Change in Percentage Points from Baseline Trend (95% CI)

Male

21.8

-2.1 (-3.2, -1.1)

-5.4 (-6.6, -4.2)

-6.8 (-8.2, -5.4)

-7.4 (-8.9, -5.9)

-7.3 (-8.9, -5.7)

Female

18.9

-2.4 (-3.4, -1.3)

-5.1 (-6.3, -3.9)

-7.7 (-9.1, -6.3)

-8.6 (-10.0, -7.1)

-8.1 (-9.8, -6.5)

 

 

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