Principal investigator: Bruno Benevit
Authors: Sarah Miller, Norman Johnson and Laura R. Wherry
Original title: Medicaid and Mortality: New Evidence from Linked Survey and Administrative Data
Location of the Intervention: United States
Sample Size: 566.000 individuals
Sector: Health Economics
Primary Variable of Interest: Mortality
Type of Intervention: Health insurance eligibility
Methodology: Difference-in-Differences, Event Study
Summary
The relationship between health insurance and mortality is still a widely discussed topic in the field of health economics. In the United States, the program Medicaid It enables access to health insurance for the poorest populations, although there is heterogeneity in the implementation of the program among the country's federative entities. The objective is to evaluate the effectiveness of... MedicaidThis study aimed to evaluate how the increase in enrollments in the program after its expansion impacted the mortality of elderly individuals, as well as to identify the adult groups most likely to benefit from the program. The results revealed that individuals from states that experienced the expansion of program eligibility increased their health insurance coverage and reduced their annual mortality rate by approximately 10%.
- Policy Problem
The relationship between health insurance and mortality is a topic constantly debated in the health economics literature. In this context, socioeconomic conditions play a critical role in access to health services, which are mostly covered by health insurance. As a consequence, individuals with incomes close to the US federal poverty level (FPL) have a mortality rate four times higher than individuals with incomes four times above the FPL.
In the United States, the Medicaid It is the main health program at the federal level, with eligibility criteria for beneficiaries and aiming to expand access to health services for the poorest segment of the country's population. With the goal of expanding health insurance coverage, the federal law... Affordable care The American Convention on Health (ACA) was enacted in 2010, expanding health insurance coverage to individuals in several states. In this sense, assessing the impact of expanding health insurance coverage on mortality in the affected population is crucial for improving the effectiveness of health policies.
- Policy Implementation Context
Expanding eligibility for Medicaid The ACA played a crucial role in reducing health disparities in the United States, marking the largest expansion of health insurance coverage since its creation. Medicare e Medicaid in 1965. Since the implementation of the ACA, more than 20 million people have received coverage, with the majority being low-income adults who receive assistance through the Medicaid.
According to the authors (MILLER; JOHNSON; WHERRY, 2021), the related literature presents evidence that this expansion has significantly improved access to effective medical care that beneficiaries would not otherwise have, including medications that reduce mortality, early diagnosis and treatment of treatable cancers, as well as visits to hospitals and emergency departments for conditions requiring immediate care.
In 2014, the expansion of Medicaid The ACA included all adults from families with incomes below 138% of FPL, expanding coverage that was previously restricted to pregnant women, adults with disabilities, and very low-income parents. A 2012 U.S. Supreme Court decision made the expansion optional for states, resulting in only 29 states and the District of Columbia adopting the measure in 2014, with seven more states joining in subsequent years. This state adoption represented a historic expansion in insurance coverage, with approximately 13,6 million adults gaining coverage. Medicaid under the ACA.
- Evaluation Details
To conduct the analysis, the study linked individuals from three different data sources. First, it used restricted data from the 2008 to 2013 waves of... American Community Survey (ACS). The selected respondents were those who, based on their pre-ACA characteristics, were likely to benefit from the expansions of Medicaid According to the ACA, only individuals in families with income equal to or less than 138% of the FPL or who have less than a high school diploma were considered. This last criterion is used to identify individuals of low socioeconomic status who may not meet the income limit at the time of the ACS interview.
The primary analysis was limited to individuals aged 55 to 64 in 2014, an age group with relatively high mortality rates. Residents of four states and the District of Columbia, which expanded the Medicaid For low-income adults prior to 2014, data were also excluded. In total, approximately 566.000 respondents met the criteria for the main sample. This data is then linked to the Census Numident file. The Census Numident file is derived from the SSA Numident Identification file, which includes information on date and county of birth and date of death for individuals with a Social Security number. The annual mortality rate is approximately 1,4% for the sample on average, and approximately 1,3% among respondents in expanding states in the year prior to expansion.
- Method
As an empirical strategy, the study adopted an Event Study model to evaluate the evolution of relative outcomes among states that experienced the expansion of eligibility for Medicaid In comparison to other states, this model allows for controlling fixed effects of state and national trends, identifying heterogeneous temporal effects of the expansion of the Community Health Agent (CHA) associated with each period before and after the intervention. Observations were established at the individual-period level. The outcome variables considered identified death and coverage of individuals through various measures in a given period (year). The intervention variable of interest identified the occurrence of expansion in the state of individuals in the respective period. All analyses considered sample weights of the CHA, and robust errors were grouped at the state level.
Furthermore, the Difference-in-Differences (DD) method was adopted to estimate the effect of Medicaid expansions after the implementation of the ACA. The analysis replaces event study indicators with a single variable that denotes states with expansion during the post-implementation period. This indicator identifies the intervention from the year of expansion for each state. The fixed sample, composed of adults aged 55 to 64 in 2014, ages over time, resulting in increasing mortality rates. The DD method considers the mortality trajectory of this group and constructs a “counterfactual” rate for expanding states, adjusting for both sample aging and the reduction in mortality due to expanded Medicaid coverage.
- Main results
The results of the expansion of Medicaid According to the ACA, significant increases in insurance eligibility and coverage were observed for individuals in the affected states. Individuals in these states experienced significant increases in eligibility for the Medicaidenrollment in the program and health insurance coverage compared to states that did not expand. The likelihood of an individual being enrolled in the program Medicaid The rate of insured individuals increased by 12,8 percentage points (pp), while the rate of insured individuals decreased by 4,4 pp. These effects were substantially greater than those observed in previous studies, indicating that individuals with low incomes and less education were the most affected by the expansion, given the selection criteria considered in this study.
Regarding the intensive use of MedicaidThe estimates revealed an increase in the number of cumulative days and years of program coverage. Individuals in expanding states experienced an average of 43 additional Medicaid enrollment days per year compared to those in non-expanding states. When accumulated, this resulted in a significant increase of 0,38 additional years of coverage. Medicaid, adding approximately 0,67 years to the end of the study period. These results highlighted how the expansion of Medicaid The ACA not only increased eligibility and immediate coverage, but also promoted greater exposure and ongoing benefits over time for covered individuals.
Regarding mortality, the results of the expansion of Medicaid Analysis of ACA data revealed a significant reduction in mortality rates among individuals in affected states. Before expansion, mortality rates were similar between states with and without expansion. However, from the first year of expansion, a significant drop in mortality was observed in expanding states compared to non-expansion states. The probability of annual mortality decreased by 0,089 pp in the first year, by more than 0,1 pp in subsequent years, and by 0,208 pp in the third year. These reductions in mortality were statistically significant and indicated a growing impact over time. On average, expansion resulted in a 0,132 pp reduction in annual mortality, representing a decrease of approximately 9,4% compared to the sample average. The analysis also revealed that mortality due to internal causes and controllable health factors showed a significant reduction, while deaths from external causes did not undergo significant change.
- Lessons in Public Policy
This article assessed how the expansion of Medicaid The ACA affected health insurance coverage and mortality. The estimates identified indicated that states that expanded the Medicaid They experienced a significant increase in eligibility and in program coverage and utilization, both at the extensive and intensive margins. Furthermore, the results revealed a reduction in mortality. Specifically, a relevant decrease in the probability of annual mortality was observed, with the effects intensifying over the years. The analysis also revealed that the reduction in mortality was more pronounced for causes of death treatable with healthcare, while deaths from external causes did not undergo significant changes.
The results of this article help to identify the positive impacts of the expansion of Medicaid regarding the health of beneficiaries, providing useful information for public policy makers seeking to expand health coverage for socioeconomically vulnerable populations and reduce mortality. This evidence highlights that policies to expand access to Medicaid They may have great potential in improving the health of populations without access to such services.
References
MILLER, S.; JOHNSON, N.; WHERRY, LR Medicaid and Mortality: New Evidence From Linked Survey and Administrative Data. The Quarterly Journal of Economics, v. 136, no. 3, p. 1783–1829, 30 jun. 2021.
