SHADAC creates and disseminates trusted methodological resources to support health policy research using survey and other data sources. These resources include publications comparing data sources for research use, sample size analyses, and methodological and instructional resources for collecting and analyzing data about health insurance coverage and access to care. SHADAC also provides tailored technical assistance to support specific research and methods related questions.
See examples and a list of SHADAC’s Research Methods Support resources below.
Related SHADAC Projects
Comparing Federal Government Surveys That Count the Uninsured, Annual Brief
Understanding and analyzing the number of people in the United States without health insurance coverage, often referred to as the “uninsured”, has long been a focus area at SHADAC. Oftentimes, federal survey data is a reliable source of estimates of uninsurance nationally or at the state-level. Important to note, however, is the variation in estimates between surveys as a result of varying survey design, data collection processes, and other factors.
To help data users, policymakers, and other interested persons understand the ways that these surveys work to measure the number of uninsured persons in the U.S., SHADAC produces an annual brief entitled “Comparing Federal Government Surveys that Count the Uninsured.” This brief provides up-to-date and past uninsurance estimates from the ACS, CPS, MEPS, NHIS, and BRFSS, examines the differences in estimates between these five federal surveys, and offers discussion on the primary factors that may have contributed to differences in estimates and the impacts of recent events or policies such as the COVID-19 pandemic and the Medicaid unwinding.
Find the latest version of this brief here.
MACPAC Survey Sample Size Analysis
The Medicaid and CHIP Payment and Access Commission contracted with SHADAC to conduct a review and sample size analysis of 13 federal population health surveys. This work assesses the quality and availability of federal survey data related to health care access, use, and outcomes for key subpopulations that frequently experience health inequities.
The resulting brief provides an overview of each of the 13 federal surveys analyzed along with sample size analysis for disability, primary language, limited English proficiency (LEP), and sexual orientation and gender identity (SOGI).
Work with IPUMS
SHADAC has developed expertise and a deep understanding of the publicly available health survey data. For over 14 years, SHADAC has collaborated with the Institute for Social Research and Data Innovation in their work to harmonize the data and documentation produced by the NHIS and the MEPS. The IPUMS Health Survey project allows users to create free, individual-level customized data extracts for analysis to support time trend analysis through consistent variable coding and production of publicly available microdata. This involves the creation of more than 2,000 integrated variables with comprehensive metadata along with documentation to support a broad audience of data users.
Most recently, SHADAC has consulted on updating documentation following the 2019 redesign of the NHIS, and on using the MEPS-HC to develop measures of health insurance coverage stability and fragmentation over time and within families and households. For individuals, we have used the two-year panel design of the MEPS to describe health insurance coverage discontinuity and associated health care access and utilization.
SHADAC has also developed an original measure of a Health Insurance Unit (HIU), which is used by a wide range of health services researchers and is the only family HIU featured on IPUMS USA. Initially created in 2012, the SHADAC HIU was made to aid researchers in reconciling the differences between the way that a “family” is defined in federal surveys with the way a “family” is defined by most private and public insurance programs. Mostly used for analyzing health insurance coverage, the SHADAC HIU has been updated over time to align with policy and program eligibility rules.
Learn more about the SHADAC HIU here.
Resources to Assist Researchers, State Analysts, and More
SHADAC has decades of experience evaluating and tracking developments in federal survey data collection and related methodology for state-level analyses. This includes keeping abreast of new survey data sources, changes to existing sources (such as changes to data collection methods), impacts of external events, and monitoring ongoing issues (like the undercount of Medicaid coverage in surveys or the uncertainty of continued availability of federal health survey data, for example). SHADAC creates and updates a variety of resources to assist researchers, state analysts, and other data users in the understanding and use of survey and other data sources for public health and state health policy research.
A list of these resources can be found below:
- Health Insurance Unit (HIU)
- Defining Family for Studies of Health Insurance Coverage
- Primary Source of Coverage Hierarchy for American Community Survey (ACS) Estimates
- Methods for Calculating Income as a Percent of the Federal Poverty Guidelines (FPG) in the Behavioral Risk Factor Surveillance System (BRFSS)
- Significance Testing on State Health Compare
- Changing Population Estimates: Implications for Data Users