Panel Paper: Isolating the Impact of Medicaid Expansion: Changes in Coverage, Access, and Preventive Care after Medicaid Expansion in Higher- vs. Lower-Need Areas

Saturday, November 4, 2017
Acapulco (Hyatt Regency Chicago)

*Names in bold indicate Presenter

Joseph A Benitez, University of Louisville and Benjamin Sommers, Harvard University

Medicaid expansion under the Affordable Care Act (ACA) extended insurance to millions of low-income Americans. However, heterogeneity in effects across expansion states has only recently garnered attention in the research as well as the policy communities. In particular, the more substantial effects of the coverage expansions were concentrated in areas with higher pre-ACA densities in uninsurance. Utilizing geographic variation in pre-expansion coverage and poverty rates are useful in characterizing the populations participating in the expansion. However, one area not explicitly discussed in this growing literature is pre-expansion variation in expressed medical needs—in particular, area-level concentrations in delayed or foregone medical needs due to financial constraint. The purpose of this work is to better understand the heterogeneity of the ACA’s impact by level of expressed cost-related unmet medical need, and provide an additional strategy for isolating the impacts of the ACA’s coverage reforms.

We use the 2011 to 2015 waves of the Behavioral Risk Factor Surveillance System (BRFSS) to compare changes in coverage, affordability, and preventive care utilization in states expanding Medicaid to states not expanding Medicaid. Our empirical approach is a difference-in-difference-in-differences (i.e. triple difference) estimation strategy, and because the BRFSS includes the date of the interview, we can account for the precise timing of each expansion states’ implementation of their Medicaid eligibility expansion, and focus our analysis to adults with incomes below 138 percent of the Federal Poverty Limit.

Higher-need areas were generally concentrated in the South, and their populations were disproportionately racial/ethnic minorities. By 2015, we observe 5 percentage point (pp) (p<0.01) uptake in having health insurance coverage—among residents from the lowest category (i.e. quartile) of pre-expansion need—however, the uptake was more four times as large (-22 pp [p<0.01]) among residents from areas in the highest category of ‘need.’ The pattern was similar regarding the expansion’s effect on the likelihood of experiencing a cost-related barrier to care. In terms of magnitude, the financial difficulty in access to care reduction was almost 2.4 times as large among expansion residents of areas with the highest concentration of need (-9.5 pp [<0.01]) compared to areas with the least concentrated need (-3.9 pp [p<0.05]).

People are uninsured for a variety of factors such as a low demand for medical care; however, using pre-expansion variation in expressed cost-related barriers to utilizing health care, adds more to what we know about the populations being helped, and how, by state policies extending Medicaid eligibility to a larger share of their low-income population. Because the magnitude of the coverage uptake and potential access improvements were larger in areas with baseline higher densities of delayed or foregone medical care because of financial constraints, we can more confidently say the Medicaid expansion component of the ACA largely benefited some of the most economically disadvantaged U.S. citizens. Furthermore, our results suggest their experiences in regular use of the health care system was largely improved through the Medicaid expansion.