The Effect of Medicaid Expansion on Mortality Disparities and Poverty - Medicaid expansion under the Affordable Care Act, wherein states have the option to expand
Medicaid coverage to adults with household incomes up to 138 percent of the federal poverty
level, has been shown to reduce mortality rates nationwide. From 2014 to 2018, mortality rates
dropped 3.6% more in states that expanded Medicaid than those that did not. Although the impact
of Medicaid expansion on mortality is well-documented, its impact on mortality disparities remains
underexamined. The overarching goal of this study is to identify the relationship between Medicaid
expansion and rural-urban ethnoracial disparities, while also estimating the mediating role of
poverty alleviation in this relationship. This study is significant because it: 1) focuses on mortality
disparity reduction instead of the simple reduction of mortality, 2) analyzes the impact of Medicaid
expansion on intersectional mortality disparities, meaning disparities found at the intersection of
multiple health disparity populations (e.g. black and rural), and 3) identifies the indirect effect of
Medicaid expansion on intersectional mortality disparities through poverty alleviation. The
innovations of this project center on three contributions. First, it will provide an explicit analysis of
mortality disparity reduction as opposed to just aggregate impacts on different groups; Second,
the study will generate an updated and improved cost-of-living adjustment for the Supplemental
Poverty Measure, as well as county-level estimates of the Supplemental Poverty Measure. Third,
the study will provide a robust analysis of the mediating role of poverty in the relationship between
Medicaid expansion and intersectional mortality disparity reduction. The project will be completed
through three specifics aims. In Aim 1, we will estimate the effect of Medicaid expansion on
ethnoracial mortality disparities by rural-urban status from 2011 to 2019. We will do so using time-
varying difference-in-difference design with marginal prediction analysis via census data and
restricted data from the National Vital Statistics System. In Aim 2, we will improve the cost-of-
living adjustment in the existing Supplemental Poverty Measure and estimate the improved
measure at the county level from 2011 to 2019. We will do so using restricted American
Community Survey and Current Population Survey data housed in the Federal Statistical
Research Data Centers to create a county-specific cost-of-living adjustment and corresponding
county-specific poverty thresholds. In Aim 3, we will estimate the mediating role of poverty
reduction in the relationship between Medicaid expansion and rural-urban ethnoracial mortality
disparities from 2011 to 2019. We will do so by integrating our estimates of the supplemental
poverty measure with our difference-in-difference models from Aim 1.
