placeholder SEPTEMBER 2014 Comparing Federal Government Surveys that Count the Uninsured: 2014 placeholder AUTHORS Colin Planalp Julie Sonier Joanna Turner State Health Access Data Assistance Center (SHADAC) SUGGESTED CITATION Planalp, C., Sonier, J., Turner, J. 2014. “Comparing Federal Government Surveys that Count the Uninsured: 2014.” Minneapolis, MN: State Health Access Data Assistance Center, University of Minnesota ABOUT SHADAC The University of Minnesota’s State Health Access Data Assistance Center (SHADAC) helps states monitor rates of health insurance coverage and understand factors associated with uninsurance. SHADAC provides targeted policy analysis and technical assistance to states that are conducting their own health insurance surveys and/or using data from national surveys. SHADAC’s work is funded by the Robert Wood Johnson Foundation. More information is available at www.shadac.org. State Health Access Data Assistance Center shadac@umn.edu Phone (612) 624-4802 September 2014 2 Comparing Federal Government Surveys that Count the Uninsured Timely and accurate estimates of the number of people who do not have health insurance coverage are important for understanding trends in health insurance coverage and the impacts of policy changes that affect health insurance. Estimates of the number of people who are uninsured are available from several different sources. This brief provides an annual update to comparisons of uninsurance estimates from five federal surveys.1 It presents trends in national estimates of uninsurance, presents the most recent available state- level estimates from these surveys, and describes the main reasons for variation in the estimates across the different surveys. FEDERAL GOVERNMENT SURVEYS USED TO ESTIMATE THE NUMBER OF PEOPLE WITHOUT HEALTH INSURANCE This brief compares five federal surveys that are used to estimate the level of uninsurance in the United States. These include:  The American Community Survey (ACS): Conducted by the U.S. Census Bureau, the ACS is an annual household survey that replaced the decennial census long form questionnaire. A question on health insurance coverage was added to the ACS in 2008.  The Behavioral Risk Factor Surveillance System (BRFSS): Sponsored by the U.S. Centers for Disease Control and Prevention, the BRFSS is a state-based survey of adults focusing on population health, risk factors, and health behaviors. Since 1991, it has included a question that asks whether respondents are uninsured or have some form of health insurance. 2  The Current Population Survey (CPS): The CPS is conducted by the U.S. Census Bureau for the Bureau of Labor Statistics, and the survey’s Annual Social and Economic Supplement (ASEC) collects data on health insurance coverage. The CPS estimates of health insurance coverage are among the most commonly cited estimates, and they are used to monitor both state and national trends in health insurance coverage. The estimates date back to 1987.  The Medical Expenditure Panel Survey – Household Component (MEPS-HC): The MEPS-HC is sponsored by the Agency for Healthcare Research and Quality, and consists of several interviews with the same respondents over two full calendar years. Conducted since 1996, the MEPS-HC collects data on health status and health conditions, health insurance coverage, access to and utilization of health care services, medical expenditures, and various demographic and socioeconomic characteristics.  The National Health Interview Survey (NHIS): Sponsored by the National Center for Health Statistics, the NHIS includes questions about health insurance coverage, health care utilization and access, health conditions and behaviors, and general health status, in addition to demographic and socioeconomic characteristics. The NHIS has been conducted annually since 1957; annual health insurance coverage estimates are available beginning with 1998. September 2014 3 Each of these surveys was designed to collect information for different research and policy purposes. Table 1 summarizes key information from each of these surveys, such as who is included in the survey, when and how the survey is conducted, response rates, and the availability of state-level health insurance estimates. In addition to collecting data on uninsurance, most of these surveys also have undergone revisions to help them measure effects of the Patient Protection and Affordable Care Act. 3 TABLE 1: Comparison of Federal Surveys Used to Estimate Uninsurance ACS BRFSS CPS MEPS-HC NHIS Census Bureau Centers for Bureau of Labor Agency for National Center Disease Control Statistics, U.S. Healthcare for Health and Prevention Dept. of Labor Research & Statistics, Centers Sponsor(s) (conducted by (conducted by the Quality for Disease states) Census Bureau) (conducted by Control and Census Bureau) Prevention General Population health, Labor force Health care Population health household survey, risk factors, and participation and access, Primary focus replaced health behaviors unemployment utilization, and decennial census cost long form Entire population Adult civilian Civilian non- Civilian non- Civilian non- Target non- institutionalized institutionalized institutionalized population institutionalized population population population population Address-based Telephone-based Address-based NHIS Address-based (National Master (households with (Census 2000 respondents (Census 2000 Address File) landline sampling frame sampling frame Sample frame telephones, plus updated with new updated with new cell phones added construction) construction) in the 2011 survey) Mail; in-person; Phone In-person; phone In-person In-person Data collection phone; and mode internet Point in time Point in time; All of prior Point in time; all Point in time; all uninsured at some calendar year; of prior year; if of prior year; if point in the past point-in-time uninsured, length uninsured, length Type of year (an optional (added in 2014) of time of time uninsurance question adopted uninsured; uninsured; measures by 38 states and uninsured at some uninsured at some the District of point in the past point in the past Columbia in year year 2013) Health No No Yes Yes Yes insurance coverage: verification question for uninsured No No Yes Yes Yes State-specific names included for Medicaid/CHIP September 2014 4 ACS BRFSS CPS MEPS-HC NHIS 89.9% (2013) 46.4% 79.5% (2013) 61.3% (2012) 75.7% (2013) (2013 combined landline/cell Response rate phone median response rate for states) Monthly Monthly February through Panel over 2 February, May, Survey period April calendar years August, November State health 50 states and D.C. 50 states and D.C. 50 states and D.C. Not published 43 states insurance estimates 2008 to 2013 1991 to 2013 1987 to 2013 1996 to 2012 1998 to 2013 (plus limited (plus first quarter Years available point-in-time of 2014) estimates for 2014) NATIONAL ESTIMATES Table 2 shows the most recent available estimates of uninsurance from each of the five surveys. As described in Table 1, some of the surveys produce estimates of the number of adults who were uninsured for an entire year, while others estimate uninsurance at a specific point in time (i.e., at the time of the survey), and some collect multiple measures of uninsurance. CPS produces the highest estimate of the number of people without health insurance coverage for the entire year, at 42 million people, and the NHIS produces the lowest, at 33.4 million. The range of the point in time estimates is much smaller (from 45.2 million to 44.8 million people). TABLE 2: Comparison of Uninsurance Estimates Survey Time Period Uninsured for the Entire Year Uninsured at a Specific Point in Time Number (millions) % of population Number (millions) % of population Total population ACS 2013 N/A N/A 45.2 14.5% CPS 2013 42.0 13.4% N/A N/A MEPS 2012 39.8 12.7% N/A N/A NHIS 2013 33.4 10.7% 44.8 14.4% Non-elderly adults (ages 18 to 64) ACS 2013 N/A N/A 39.5 20.3% BRFSS 2013 N/A N/A 41.2 21.1% CPS 2013 35.8 18.4% N/A N/A MEPS 2012 35.8 18.4% N/A N/A NHIS 2013 30.5 15.7% 39.6 20.4% Sources: CPS estimates from U.S. Census Bureau, 2014, "Health Insurance Coverage in the United States: 2013"; ACS estimates for civilian noninstitutionalized population from U.S. Census Bureau, 2014, "Health Insurance Coverage in the United States: 2013" and American Fact Finder, accessed September 18, 2014; NHIS estimates from Cohen and Martinez, 2014, “Health Insurance Coverage: Early Release of Estimates from the National Health Interview Survey, 2013”; MEPS estimates from http://meps.ahrq.gov/mepsweb/data_stats/summ_tables/hc/hlth_insr/2012/alltablesfy.pdf. BRFSS estimates analyzed by SHADAC using 2013 public use file. September 2014 5 In addition, two surveys have released estimates of point-in-time uninsurance from early 2014. The NHIS point-in-time estimate is 13.1 percent of the population (41.0 million people). The CPS point-in-time uninsurance rate estimate is 13.8 percent of the population, though an estimate of the number of uninsured was not released in September 2014 along with the rate. While the NHIS’ early 2014 estimate can be compared against point-in-time estimates from previous years, the CPS point-in-time estimate of uninsurance is based on new survey questions, so comparable data do not exist for prior years. It is important to note that these estimates come from surveys conducted during the Affordable Care Act’s first open enrollment period, with the NHIS being conducted from January to March and the CPS being conducted from February to April 2014. NATIONAL TRENDS Over time, the uninsurance estimates from these surveys have demonstrated similar national trends, as shown in Figure 1. Together, the surveys show a decrease in the number of uninsured people since 2011. Before then, the surveys showed a steady increase over several years in the number of people who were uninsured. Additionally, the three surveys (ACS, BRFSS and NHIS) with comparable data between 2012 and 2013 also show a decrease in the number of uninsured for this most-recent time period. With its estimate from the first quarter of 2014, the NHIS also shows this trend of declining uninsurance continuing. The CPS estimate of uninsurance in early 2014 cannot be used to evaluate a trend because this is the first time the survey has produced a point-in-time estimate. When examining trends in uninsurance, it is important to consider that similar to the way estimates across different surveys may not be comparable, estimates within the same survey may not always be comparable over time. This can be due to changes in survey questions and changes in methodology:  Changes in BRFSS: In 2011, the BRFSS began using a new sampling frame, adding cell phones to the landlines it historically had sampled. This revision was intended to capture the growing segment of the U.S. population that uses cell phones exclusively, allowing the survey estimates to more closely reflect the overall population.4 Because of this change, the CDC advises against comparing estimates since 2011 against those in 2010 or before.5  Changes in CPS: In 2014, the CPS was fielded with a revised set of survey questions designed to improve the accuracy of its uninsurance estimate, which researchers have suggested more closely resembled a point-in-time measure than its intended measure of insurance during the previous year.6,7,8 These new data beginning in 2013 will not be comparable to data from 2012 and earlier. This is not the first time the CPS has undergone revisions that have created a break in its time series. In 2000, the survey added a verification question, asking people who did not report coverage whether they were in fact uninsured.9 While this change improved the accuracy of the uninsurance estimate by allowing respondents to confirm their coverage status, it also caused a break in the comparability of CPS estimates from 1998 and earlier versus 1999 and later.10 The CPS also has made methodological changes that could affect the comparability of its estimates over time, such as changes in weighting of data.11 September 2014 6 FIGURE 1. Trend in Number of Uninsured, 2000 to 2013 (ACS, BRFSS, and NHIS point-in-time estimates of the uninsured; CPS and MEPS estimates of the full-year uninsured) All Ages 50.0 Number Uninsured (Millions) 45.0 ACS 40.0 CPS* MEPS 35.0 NHIS 30.0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 (Q1) Nonelderly Adults (Ages 18 to 64) 45.0 Number Uninsured (Millions) 40.0 ACS BRFSS* 35.0 CPS* MEPS 30.0 NHIS 25.0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Children (Ages 0 to 17) 20.0 Number Uninsured (Millions) 15.0 ACS 10.0 CPS* MEPS 5.0 NHIS 0.0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 *Note: Dashed line represents a break in series. BRFSS data beginning in 2011 and CPS data beginning in 2013 are not comparable to earlier estimates. Sources: CPS estimates from U.S. Census Bureau, 2014, "Health Insurance Coverage in the United States: 2013"; ACS estimates for civilian noninstitutionalized population from U.S. Census Bureau, 2014, "Health Insurance Coverage in the United States: 2013" and American Fact Finder, accessed September 18, 2014; NHIS estimates from Cohen and Martinez, 2014, “Health Insurance Coverage: Early Release of Estimates from the National Health Interview Survey, 2013”; MEPS estimates from http://meps.ahrq.gov/mepsweb/data_stats/summ_tables/hc/hlth_insr/2012/alltablesfy.pdf. BRFSS estimates analyzed by SHADAC using 2013 public use file. September 2014 7 STATE-LEVEL ESTIMATES The CPS, ACS and BRFSS are designed to produce state-level estimates for all 50 states and the District of Columbia. Insurance coverage estimates from NHIS are published for 43 states, and no state-level estimates of insurance coverage are published from the MEPS-HC. Table 3 presents the most recent state-level estimates of uninsurance from the ACS, BRFSS, and NHIS (standard errors are shown in Appendix). As with the national estimates, the estimated level of uninsurance for states varies across surveys; however, general patterns are consistent (e.g., states with low uninsurance rates are low in all three surveys). FACTORS CONTRIBUTING TO DIFFERENCES IN SURVEY ESTIMATES There are many reasons why health insurance estimates vary across surveys. The surveys are designed to fulfill different goals, and use different questions, statistical designs, and data collection and processing methods. Each of these factors likely contributes to differences in uninsurance estimates. Specific differences include the following:  Conceptual differences in measures of uninsurance: As noted earlier, some surveys collect information about whether a person lacked health insurance coverage for a full year, while others collect information on point in time insurance status, and some collect multiple measures.  Reference period: The CPS Annual Social and Economic Supplement, conducted in February through April each year, has historically asked respondents about their health insurance coverage during the entire previous calendar year, with respondents being asked to report their coverage for a time period as long as 16 months prior to the interview. Beginning with data collected in 2013, the CPS asks respondents about their current coverage status (point in time), as well as the current year- to-date and previous calendar year (up to 16 months). For their measures of coverage during the prior year, NHIS and MEPS have shorter recall periods than the CPS. Like the redesigned CPS, the ACS and BRFSS also collect information about current coverage. These differences in the time period for which coverage is being reported contribute to differences in the survey estimates; in addition, differences in the length of time that respondents are being asked to recall their insurance coverage status can also result in differences in measurement error across the surveys. 12 As mentioned above, many researchers believe that the CPS pre-2013 measure is closer to a point-in-time measure of uninsurance than a full-year measure.13  Differences in survey questions: Differences in the ways that health insurance questions are asked can lead to differences in uninsurance estimates. For example, when the Census Bureau added a “verification question” to the CPS in 2000 that asked people who did not report any coverage if they were in fact uninsured for all of 1999, the estimated number of people without health insurance declined by 8 percent, from 42.6 million to 39.3 million. 14 The CPS, NHIS, and MEPS all verify insurance status for people who do not report any of the specific types of coverage that the survey asks about, but the ACS and BRFSS do not. Another difference in survey questions that can lead to different estimates across surveys is the fact that some of the surveys (CPS, NHIS, and MEPS) use state-specific names for Medicaid and Children’s Health Insurance Program (CHIP) programs, while the ACS and BRFSS do not. September 2014 8  Missing data and imputation: Some of these surveys have processes in place to manage missing data and impute missing values. In the CPS supplement that includes the health insurance questions, about 10 percent of the respondents do not answer any questions, and the missing values are imputed by the Census Bureau. Similarly, in the 2008 ACS about 11 percent of responses had one or more of the health insurance items missing; these missing data were imputed by the Census Bureau. In contrast, the NHIS and MEPS impute little or no health insurance coverage, because the data are much more complete than the CPS or ACS. The BRFSS does not impute health insurance coverage. CONCLUSION Federal surveys are essential resources for estimating the number of uninsured. As coverage reforms are implemented, we expect to see changes in health insurance coverage nationwide and across states. Each survey provides a unique view of the problem of uninsurance, and together the surveys provide a wealth of information about how uninsurance varies by population characteristics, and how it is associated with differences in access to and use of health care services, as well as health status. For state-level analysis, the ACS and CPS are both commonly used; however, the Census Bureau has not yet published state-level estimates from the CPS for 2013, and these CPS estimates cannot be compared to prior years. Surveys produce different estimates because they have different sampling methodologies, survey questions, data collection, and editing procedures. Understanding these differences is important, but it should not distract policymakers from the need to address issues of cost and access for those without health insurance coverage. September 2014 9 TABLE 3. State-Level Estimates of Uninsurance from Federal Surveys, 2013 (Percent of Population Uninsured) Total population Non-elderly adults (ages 18 to 64) ACS NHIS ACS BRFSS NHIS Point in time Point in time Point in time Point in time Point in time United States 14.5 14.4 20.3 21.1 20.4 Alabama 13.6 11.1 20.1 21.2 17.3 Alaska 18.5 * 23.8 20.2 * Arizona 17.1 18.0 23.5 25.3 23.4 Arkansas 16.0 18.5 24.1 28.3 27.5 California 17.2 17.0 24.0 20.3 23.7 Colorado 14.1 13.3 18.8 20.0 18.3 Connecticut 9.4 9.1 13.2 12.3 13.2 Delaware 9.1 9.3 12.9 14.3 13.8 District of Columbia 6.7 3.5 8.7 9.9 4.7** Florida 20.0 20.5 28.8 29.1 29.1 Georgia 18.8 19.7 25.9 27.3 27.2 Hawaii 6.7 * 9.6 10.0 * Idaho 16.2 17.0 23.0 24.1 24.3 Illinois 12.7 12.4 18.4 19.4 17.8 Indiana 14.0 12.7 19.2 20.9 19.0 Iowa 8.1 7.4 11.6 12.7 11.3 Kansas 12.3 12.7 17.5 20.8 19.5 Kentucky 14.3 16.4 20.6 22.0 24.1 Louisiana 16.6 13.1 24.2 26.0 19.8 Maine 11.2 10.4 15.9 15.3 15.9 Maryland 10.2 11.4 14.1 15.5 16.4 Massachusetts 3.7 4.6 5.2 7.2 6.0** Michigan 11.0 11.0 16.0 17.4 15.8 Minnesota 8.2 7.1 10.9 12.9 9.7 Mississippi 17.1 16.7 24.7 28.1 24.2 Missouri 13.0 14.6 18.3 18.8 20.1 Montana 16.5 * 23.0 21.5 * Nebraska 11.3 12.5 16.1 17.6 18.5 Nevada 20.7 21.7 27.0 27.3 29.3 New Hampshire 10.7 10.6 15.4 15.6 16.1 New Jersey 13.2 12.0 18.6 19.4 17.5 New Mexico 18.6 * 26.9 26.2 * New York 10.7 9.6 15.0 17.0 13.6 North Carolina 15.6 17.0 22.6 24.2 25.6 North Dakota 10.4 * 13.4 12.4 * Ohio 11.0 11.4 15.7 16.7 16.3 Oklahoma 17.7 20.2 24.7 22.6 28.3 Oregon 14.7 14.2 21.2 25. 20.4 Pennsylvania 9.7 11.4 13.5 15.2 16.4 Rhode Island 11.6 9.1 16.2 18.7 13.1 South Carolina 15.8 16.1 22.9 23.9 23.2 South Dakota 11.3 * 15.9 14.9 * Tennessee 13.9 10.0 20.0 21.2 16.2 Texas 22.1 20.6 29.9 32.8 28.4 Utah 14.0 15.3 18.5 19.2 20.7 Vermont 7.2 * 10.2 11.5 * Virginia 12.3 11.9 17.2 18.4 16.0 Washington 14.0 16.4 19.8 20.6 23.4 West Virginia 14.0 20.1 20.7 23.7 28.8 Wisconsin 9.1 8.2 12.8 14.2 11.1 Wyoming 13.4 * 19.2 23.6 * * NHIS does not release estimates for some states due to sample size. ** The NHIS recommends using estimates from these states with caution because of their relative standard errors between 30% and 50%. Sources: ACS estimates for civilian noninstitutionalized population from U.S. Census Bureau, 2014, "Health Insurance Coverage in the United States: 2013" and American Fact Finder, accessed September 18, 2014; NHIS estimates from Cohen and Martinez, 2014, “Health Insurance Coverage: Early Release of Estimates Interview Survey, 2013”; BRFSS estimates analyzed by SHADAC using 2013 public use file. September 2014 10 REFERENCES 1 Annual updates to SHADAC’s brief Comparing Federal Surveys that Count the Uninsured from previous years are available at http://www.shadac.org/content/rwj-briefs-and-reports. 2 In 2013, the BRFSS added an optional module that includes a question asking whether respondents were uninsured at any point in the previous year, as well as a question on type of coverage. However, these questions were adopted by only 38 states and the District of Columbia, so national data are not available. 3 For additional information on comparing the content of these surveys, including changes related to the ACA, see SHADAC’s May 2014 issue brief “Using Recent Revisions to Federal Surveys for Measuring the Effects of the Affordable Care Act.” Available at http://www.shadac.org/publications/using-recent- revisions-federal-surveys-measuring-effects-affordable-care-act. For greater detail on recent revisions to the CPS, see SHADAC’s May 2014 issue brief “An Introduction to Redesigned Health Insurance Coverage Questions in the 2014 Current Population Survey’s Annual Social and Economic Supplement.” Available at http://www.shadac.org/publications/cpsbrief. 4 U.S. Centers for Disease Control and Prevention. 2011. “Comparability of Data: BRFSS 2011.” Available at: http://www.cdc.gov/brfss/annual_data/2011/compare_11_20121212.pdf. 5 U.S. Centers for Disease Control and Prevention. 2013. “Methodologic Changes in the Behavioral Risk Factor Surveillance System in 2011 and Potential Effects on Prevalence Estimates.” Available at: http://www.cdc.gov/surveillancepractice/reports/brfss/brfss.html. 6 Turner, J, Boudreaux, M. 2014. “An Introduction to Redesigned Health Insurance Coverage Questions in the 2014 CPS.” SHADAC Brief #39. Minneapolis, MN: State Health Access Data Assistance Center. Available at: http://www.shadac.org/publications/cpsbrief. 7 Planalp, C., Sonier, J., Turner, J. 2014. “Using Recent Revisions to Federal Surveys for Measuring the Effects of the Affordable Care Act.” Issue Brief #41. Minneapolis, MN: State Health Access Data Assistance Center, University of Minnesota. Available at: http://www.shadac.org/publications/using-recent-revisions- federal-surveys-measuring-effects-affordable-care-act. 8 Davern M., G. Davidson, J. Ziegenfuss, et al. 2007. “A Comparison of the Health Insurance Coverage Estimates from Four National Surveys and Six State Surveys: A Discussion of Measurement Issues and Policy Implications.” Final report for U.S. DHHS Assistant Secretary for Planning and Evaluation, Task 7.2. Minneapolis, MN: University of Minnesota. Available at: http://www.shadac.org/files/sha- dac/publications/ASPE_FinalRpt_Dec2007_Task7_2_rev.pdf 9 Turner, J., Boudreaux, M. 2012. “Implementation of Improvements to the Allocation Routine for Health Insurance Coverage in the CPS ASEC. Minneapolis, MN: State Health Access Data Assistance Center, University of Minnesota. Available at: http://fcsm.sites.usa.gov/files/2014/05/Turner_2012FCSM_I-C.pdf. September 2014 11 10 To improve the comparability of CPS estimates of uninsurance over time, the State Health Access Data Assistance Center (SHADAC) has created an enhanced time series of CPS data, available at: http://datacenter.shadac.org. The enhanced time series is available from 1987 to 2012. It does not bridge the re-design introduced in 2013, but SHADAC is evaluating the continuation of the enhanced series from 2013 forward. 11 State Health Access Data Assistance Center. 2010. “Comparing State Uninsurance Estimates: SHADAC- Enhanced CPS and CPS.” Issue Brief #21. Minneapolis, MN: University of Minnesota. Available at: http://www.shadac.org/files/shadac/publications/IssueBrief21.pdf. 12 Klerman JA, JS Ringel, and B Roth. 2005. Under-reporting of Medicaid and welfare in the Current Population Survey. Working Paper. Santa Monica CA: RAND, March 2005; Short PF. 2001. Counting and characterizing the uninsured. Working Paper Series. Ann Arbor MI: Economic Research Initiative on the Uninsured, December 2001; Sudman S, N Bradburn, and S Schwarz. 1996. Thinking about Answers. San Francisco: Jossey-Bass; Bhandari S. 2004. People with health insurance: A comparison of estimates from two surveys. Working Paper No. 243. Washington DC: U.S. Census Bureau, June 2004. Available at: http://www.census.gov/dusd/MAB/wp243.pdf; Lewis, K, MR Elwood, and J Czajka. 1998. Counting the uninsured: A review of the literature. Washington DC: The Urban Institute, July 1998. 13 Davern M., G. Davidson, J. Ziegenfuss, et al. 2007. “A Comparison of the Health Insurance Coverage Estimates from Four National Surveys and Six State Surveys: A Discussion of Measurement Issues and Policy Implications.” Final report for U.S. DHHS Assistant Secretary for Planning and Evaluation, Task 7.2. Minneapolis, MN: University of Minnesota. Available at: http://www.shadac.org/files/sha- dac/publications/ASPE_FinalRpt_Dec2007_Task7_2_rev.pdf 14 Nelson, C.T. and R.J. Mills. 2001. “The March CPS Health Insurance Verification Question and Its Effect on Estimates of the Uninsured.” 2001 Proceedings of the Section on Survey Research Methods, Alexandria, VA: the American Statistical Association. September 2014 12 APPENDIX. Standard Errors for Percent of Population Uninsured, 2013 Total population Non-elderly adults (ages 18 to 64) ACS NHIS* ACS BRFSS NHIS* Point in time Point in time Point in time Point in time Point in time United States 0.06 0.21 0.06 0.15 0.29 Alabama 0.24 1.39 0.30 1.00 2.14 Alaska 0.61 * 0.73 0.98 * Arizona 0.24 1.64 0.24 1.58 1.26 Arkansas 0.30 1.79 0.43 1.16 2.40 California 0.12 0.52 0.12 0.60 0.73 Colorado 0.18 1.50 0.30 0.55 1.59 Connecticut 0.24 1.30 0.36 0.68 2.44 Delaware 0.43 1.48 0.55 0.82 2.56 District of Columbia 0.36 0.90 0.43 0.94 1.80** Florida 0.12 0.84 0.18 0.72 1.21 Georgia 0.18 1.90 0.24 0.84 2.10 Hawaii 0.24 * 0.36 0.53 * Idaho 0.49 1.99 0.67 1.04 2.92 Illinois 0.12 0.86 0.18 1.01 1.16 Indiana 0.18 1.45 0.24 0.68 2.29 Iowa 0.18 1.21 0.24 0.67 1.91 Kansas 0.24 1.54 0.30 0.43 2.60 Kentucky 0.18 1.68 0.30 0.76 2.19 Louisiana 0.24 1.52 0.30 1.28 2.33 Maine 0.30 1.57 0.43 0.68 1.84 Maryland 0.18 1.44 0.24 0.67 2.21 Massachusetts 0.12 0.87 0.12 0.43 2.12** Michigan 0.12 1.02 0.18 0.61 1.38 Minnesota 0.18 1.14 0.18 0.61 1.72 Mississippi 0.30 1.67 0.43 0.97 1.74 Missouri 0.18 1.59 0.24 0.84 2.03 Montana 0.49 * 0.61 0.72 * Nebraska 0.30 1.79 0.43 0.63 2.87 Nevada 0.36 1.92 0.43 1.43 2.32 New Hampshire 0.30 1.55 0.49 0.76 2.27 New Jersey 0.12 1.17 0.18 0.61 1.90 New Mexico 0.36 * 0.55 0.82 * New York 0.12 0.69 0.12 0.66 0.87 North Carolina 0.18 1.15 0.24 0.74 1.80 North Dakota 0.49 * 0.61 0.67 * Ohio 0.12 0.87 0.12 0.64 1.09 Oklahoma 0.18 1.87 0.30 0.76 2.26 Oregon 0.24 1.55 0.30 1.02 2.35 Pennsylvania 0.12 1.02 0.12 0.57 1.43 Rhode Island 0.43 1.43 0.55 0.86 2.23 South Carolina 0.24 1.71 0.30 0.74 2.15 South Dakota 0.43 * 0.49 0.90 * Tennessee 0.18 1.39 0.24 0.95 2.26 Texas 0.12 0.93 0.18 0.83 1.32 Utah 0.30 1.50 0.36 0.56 2.04 Vermont 0.36 * 0.49 0.66 * Virginia 0.18 1.23 0.24 0.71 1.72 Washington 0.18 1.49 0.24 0.66 1.77 West Virginia 0.30 1.85 0.49 0.84 2.17 Wisconsin 0.12 1.25 0.18 0.83 2.06 Wyoming 0.55 * 0.79 0.98 * * NHIS does not release estimates for some states due to sample size. ** The NHIS recommends using estimates from these states with caution because of their relative standard errors between 30% and 50%. Sources: ACS estimates for civilian noninstitutionalized population from U.S. Census Bureau, 2014, "Health Insurance Coverage in the United States: 2013" and American Fact Finder, accessed September 18, 2014; NHIS estimates from Cohen and Martinez, 2014, “Health Insurance Coverage: Early Release of Estimates from the National Health Interview Survey, 2013”; BRFSS estimates analyzed by SHADAC using 2013 public use file. September 2014 13