Joanna Turner presented, "Medicaid Undercount in the American Community Survey: How does Minnesota Compare with other States?" at the Minnesota Health Services Research Conference on March 4, 2014. The objective of her presentation is to evaluate the Medicaid undercount in the American Community Survey (ACS) including state variation and comparisons to previous results studying the undercount in other federal surveys.

This analysis was conducted by the State Health Access Data Assistance Center (SHADAC) to estimate the geographic concentration of the uninsured across U.S. counties.  The estimates are from the 2011 Small Area Health Insurance Estimates (SAHIE) program at the U.S. Census Bureau. The SAHIE program models health insurance coverage by combining survey estimates with administrative records, population estimates, and the decennial census.  This method produces annual estimates for all counties and includes a limited set of demographic features.  The advantage of using the SAHIE is that it is the only source of annual estimates of number of uninsured for all counties. 

Full Associated Press story here.

See the interactive map here.

5-Year State and County Health Insurance Coverage Estimates
from the American Community Survey (ACS)

The tables below contain state and county health insurance coverage estimates for the pooled years 2008-2012.  These estimates come from the 5-year American Community Survey (ACS) via the U.S. Census Bureau’s American FactFinder (AFF) tool. These estimates pool together 5-years of data to produce reliable period estimates for areas and subgroups with smaller populations. This is the first time health insurance coverage estimates are available for all counties.

About the ACS

The ACS is a household survey that began in 2005 and produces annually updated data on a variety of population characteristics, including health insurance coverage. In total, the ACS surveys approximately three million US households each year. An important feature of the ACS is that it includes a large enough sample for state‐level and sub‐state estimates.

The Census Bureau publishes 1-year estimates for areas with populations of 65,000 or more; 3-year estimates (covering 36 months) for areas with populations of 20,000 or more; and 5-year estimates (covering 60 months) for all statistical, legal, and administrative entities. For an explanation of the various ACS data products see SHADAC Brief #32 “Understanding 1-, 3-, and 5-year ACS Estimates: Summary Tabulations and Public Use Files." 

The ACS began asking survey respondents about health insurance coverage during the 2008 calendar year. Specifically, the survey asks respondents about current coverage for each person in the respondent’s household. A person is categorized as “insured” if he or she has coverage at the point in time at which the survey is administered.

How Are these Estimates Different from the Estimates that SHADAC Publishes Using Census Bureau Micro-Data Files?

Two definitions used by the Census Bureau to generate the tabulations above differ from those that SHADAC uses to generate tabulations for the SHADAC Data Center and the RWJF Data Hub.  The definitional differences are as follows:

   Family

• The Census Bureau defines a family as all related people in a household.
• SHADAC defines a family using a measure called the “Health Insurance Unit” (HIU), which includes all individuals who would likely be considered a family unit in determining eligibility for either private or public coverage.
• To learn more about the HIU, see SHADAC Brief #27, “Defining Family for Studies of Health Insurance Coverage.”

   Family Income

• The Census Bureau determines family income as a percentage of the Federal Poverty Level (FPL), which is a definition of poverty used primarily for statistical purposes.  For example, FPL is used to estimate the number of Americans living in poverty each year.
• SHADAC determines family income as a percentage of the U.S. Department of Health and Human Services’ Federal Poverty Guidelines (FPG), which is a measure used for administrative purposes.  For example, FPG is used to determine eligibility for federal programs such as Medicaid and the Supplemental Nutrition Assistance Program (SNAP).
• To learn more about the difference between FPL and FPG, click here.
   

Additional Resources:

• Resources for Monitoring the ACA
  SHADAC-gathered online resources, data reports, and federal and state surveys to help monitor the Affordable Care Act.
• State Reform Survey Item Matrix (SRSIM)
  An Excel matrix with sort and filter functions that allows users to search for survey metrics and question items from existing state surveys and from three federal or foundation surveys that regularly report health insurance and access data.

In this article, authors Jean Abraham, Pinar Karaca-Mandic, and Michel Boudreaux, generate national-, regional-, and state-level estimates of the individual health insurance market using multiple federal surveys and administrative data from the National Association of Insurance Commissioners (NAIC).  They find that notable differences exist between survey estimates themselves and between survey estimates and NAIC administrative counts.

NAIC data for this study were purchased through a grant to SHADAC from the Robert Wood Johnson Foundation's State Network initiative.  

Abraham, J.M., Karaca-Mandic, P., & Boudreaux, M. 2013. "Sizing Up the Individual Market for Health Insurance: A Comparison of Survey and Administrative Data Sources." Medical Care Research and Review 70(4): 418-433.