ACA Medicaid Expansion Reduces Mortality Rates, Study Shows

July 25, 2019 - The Affordable Care Act’s Medicaid expansion could have saved 15,600 lives in the three years following its initiation if it was put into effect nationwide, according to a recent study from the National Bureau of Economic Research (NBER).

The Affordable Care Act Medicaid expansion reduced mortality by about 0.8 percent and Medicaid eligibility increased by 41 to 46 percent.

Enrollment grew by 7.3 percent in the first year after Medicaid expansion and 9.9 percent four years later. The expansion decreased the number of uninsured by 3.8 percent in the first year and 3.9 percent in the fourth year.

The result, the researchers said, is that 15,600 lives could have been saved had the Medicaid expansion been implemented nationwide as originally intended.

The study of nearly 566,000 individuals gathered data from the American Community Survey (ACS) from 2008 to 2013 and from the Census Numident, which uses Social Security data to record deaths.

Then, using data from a previous NBER study published in February 2019, they tracked individuals, who fit the same criteria, from 2014 through 2017.

Altogether, the study started with approximately 566,000 individuals and followed the trends from 2008 through 2017.

From the ACS survey material, the researchers selected only households that were likely to benefit from the Affordable Care Act. That included those who had an income that was at or higher than 138 percent of the federal poverty level (FPL), did not have a high school degree, and who were ages 55 to 64.

Individuals in this category have a higher mortality rate than the rest of the population, the researchers noted. The annual mortality rate for individuals who fall between the ages of 55 to 64 and earn less than 138 percent of the FPL had a 2.3 times higher annual mortality rate than their higher-income counterparts at 1.6 percent.

The researchers analyzed four areas in which the Affordable Care Act influenced Medicaid through expanding the program: Medicaid eligibility, Medicaid coverage, uninsurance rate decline, and the mortality rate.

Medicaid eligibility increased by 41 to 46 percent during each post-expansion year, compared to the year before the Affordable Care Act passed. And consequently, Medicaid coverage increased 7.3 percent after year one and 9.9 percent four years later.

From there, uninsurance rates decreased. After the first year, uninsurance when down by 3.8 percent and then 3.9 percent in the fourth. The estimates for the intervening years are higher but the researchers attribute this to the increased share of individuals going into Medicare.

These increases in Medicaid eligibility and enrollment were tied to lower mortality rates, the report showed.

In the first year, the probability of mortality in expansion states fell by about 0.09 percent, or 6.4 relative to sample mean. The probability of mortality continued to fall by 0.1 percent in the second year of expansion. By the fourth year after the Affordable Care Act, the expansion states had an annual mortality rate that was 0.2 percent lower than states that waived Medicaid expansion.

There is potential for inaccuracy, researchers admitted, noting that the mortality rate’s decline may be higher. Medicaid enrollment is notably underreported. By the researchers’ estimates comparing the ACS numbers to CMS data, ACS underrepresented the Medicaid population by 35 percent.

When adjusted for this miscount, the mortality rate decreased 0.8 percent in the first year, not 0.09 percent.

The numbers of Medicaid enrollees counted and surveyed in the ACS and prior NBER study may also be impacted by the fact that individuals could have moved from an expansion state to a non-expansion state during this time period or vice versa, or they could have started earning a higher income during that time.

Another limitation is that the statistics do not note the cause of death. To rectify this, the researchers supplemented that information using the ACS survey, linked to cause of death information by the Mortality Disparities in American Communities project from 2008 to 2015. This did lead to a decrease in their sample size as a result.

“Our analysis provides new evidence that Medicaid coverage reduces mortality rates among low-income adults,” the researchers concluded. “Our estimates suggest that approximately 15,600 deaths would have been averted had the ACA expansions been adopted nationwide as originally intended by the ACA. This highlights an ongoing cost to non-adoption that should be relevant to both state policymakers and their constituents.”