Panel: Impacts of the ACA on Insurance Coverage, Utilization, and Health

Saturday, November 9, 2019: 3:15 PM-4:45 PM
I.M Pei Tower: Terrace Level, Terrace (Sheraton Denver Downtown)

*Names in bold indicate Presenter

Organizer:  Jesse Hinde, RTI International, Inc.
Discussants:  Brendan Saloner, Johns Hopkins University and Kelsi G. Hobbs, University of North Carolina, Greensboro

The Affordable Care Act (ACA) has considerably reduced the uninsured rate nationally through availability of guaranteed issue commercial plans through the Marketplace and expanded Medicaid eligibility in many states. Simply expanding access to health insurance coverage may not always be enough, understanding the responsiveness of consumers to the incentive structures for enrollment and health care use are critical to future reforms that build upon or replace the ACA. One of the core arguments for expansion has been that individuals without coverage may forego preventive care, delay treatment, and subsequently overutilize the emergency department (ED)––leading to worse health outcomes and higher long-run health expenditures. In this session, we explore changes in subsidy structure on uptake of coverage and effects of coverage gains on health care use and outcomes, providing a comprehensive picture of the broad impacts of the ACA.


The first paper assesses changes in the effects of the Marketplace subsidies on insurance coverage as the ACA Marketplace premiums and regulations have evolved across states.  It leverages the Current Population survey and regression discontinuity design to identify effects of the subsidies at three eligibility thresholds where the subsidy structure changes discretely. Preliminary results suggest that coverage effects have attenuated at the lowest eligibility thresholds in Medicaid expansion states and increased in non-expansion states, and increased at higher thresholds in states running their own exchange.


The second paper studies trajectories of ambulatory care visits and ED visits among six data-derived subgroups of Pennsylvania Medicaid expansion enrollees, a state ranking fifth largest in Medicaid enrollment. Reasons for visiting the ED were similar across the six subgroups; however, reasons for non-ED ambulatory care use were highly variable (e.g., substance-related disorders, mood disorders, dental care). The results inform Medicaid agencies on the health needs and services used by millions of newly publicly insured individuals and how heterogenous subgroups may benefit from different sets of services to reduce ED utilization and improve enrollee health.


The third paper focuses on the long-run trajectory of potentially avoidable ED utilization after coverage expansion. Two well-known algorithms were used to classify ED visits in seven states using data from the Healthcare Cost and Utilization Project for 2008 through 2016. It uses one-, two-, and three-year lags of insurance coverage in a county-level fixed effects model to identify whether prior changes in population-level coverage impact future ED use, failing to find compelling evidence to suggest delayed effects of coverage gains on ED use for non-emergent or preventable conditions.


The fourth paper studies the impact of Medicaid expansion on incidence of end stage renal disease (ESRD), a costly but preventable condition. It uses a difference-in-differences design to compare incidence rates across Public Use Microdata Areas and expansion status. Medicaid expansion was associated with 1.7 fewer incident ESRD cases per million, representing a 2.5% relative reduction in incidence. This highlights a potential benefit for non-expansion states with high baseline ESRD incidence rates and demonstrates how increased Medicaid spending can generate offsetting reductions in Medicare spending, the primary payer for ESRD.

Is There a Delayed Effect of Coverage Gains on Avoidable ED Visit Rates?
Paul Shafer1, Lindsay Sabik2, Stacie Dusetzina3, Timothy Platts-Mills4, Sally Stearns4 and Justin Trogdon4, (1)Boston University, (2)University of Pittsburgh, (3)Vanderbilt University, (4)University of North Carolina, Chapel Hill

Trajectories of Emergency Department and Ambulatory Care Use in Pennsylvania Medicaid Expansion
Mara Hollander, Lindsay Sabik, Evan Cole, Jeremy Kahn and Julie Donohue, University of Pittsburgh

Effect of Medicaid Expansion on the Incidence of End Stage Renal Disease Among Nonelderly Adults
Rebecca Thorsness1, Shailender Swaminathan1, Yoojin Lee1, Benjamin Sommers2, Rajnish Mehrotra3, Kevin Nguyen1, Daeho Kim1 and Amal Trivedi1, (1)Brown University, (2)Harvard University, (3)University of Washington

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