For the last three years, the U.S. government and the governments of the 50 states and the District of Columbia have been running an experiment on live human beings.

That experiment seeks to answer the question of whether providing "free" health insurance coverage through the Medicaid welfare program to low-income earning Americans whose household incomes fall between 100% and 138% of the poverty threshold would improve their health through increased access to health care resources enough to save lives.

The 50 states and the District of Columbia were divided through a political process into two groups in 2014, when the Patient Protection and Affordable Care Act (aka "Obamacare") went into effect. In that year, the governments of 26 states and the District of Columbia had acted to expand the eligibility of these low-income earning American households for their respective Medicaid programs, while the other 24 states did not. In the 24 states that did not act to expand their state's Medicaid welfare program, low income earning households were instead eligible for highly-subsidized health insurance coverage through their state's Affordable Care Act marketplace (or ACA exchange), which they would be able to opt out of if they chose instead to pay the ACA's "shared responsibility" tax.

Divided into these two groups, between Medicaid-expansion states and non-expansion states, we should be able to tell whether the expansion of eligibility for the Medicaid welfare program for low-income earning but non-impoverished American households saved lives through the National Center for Vital Statistics' data on each state's age-adjusted mortality rates given that this portion of income earners represents a significant share of each state's population.

In theory, because the expansion of eligibility of the Medicaid welfare program should improve the access of these low-income earning households to costly health care services by eliminating the need of these households to pay for their medical treatment, we should expect to see a noticeable reduction in the mortality rates for all causes in each Medicaid-expansion state that would not be evident in the non-Medicaid expansion states.

But to do the job properly, we need to take into account any trends in age-adjusted mortality rates that existed in the period prior to the implementation of Obamacare in 2014, which establishes a counterfactual for what we should expect mortality rates from all causes to be in each state in the absence of any expansion in Medicaid eligibility.

We did that for each state and the District of Columbia for the five full years from 2009 through 2013 using linear regression, which we used to project what each state's age-adjusted mortality rate would be in 2014. We can then compare those projected results with the actual age-adjusted mortality rates that was recorded for each state in 2014, which is the most recent year for which the NCHS has published final data for deaths at this time. All that data is presented in the following table (if you're accessing this article on a site that republishes our RSS news feed. and the table hasn't been rendered properly, you can see the original here).

Collectively, from 2009 through 2013, the 26 states and the District of Columbia that acted to expand their Medicaid welfare program eligibility in 2014 averaged annual declines in their age-adjusted mortality rates of 4.0 deaths per 100,000 population. Meanwhile, the 24 states that did not expand their Medicaid welfare program eligibility in 2014 saw an average annual decline in their mortality rates of 1.3 deaths per 100,000 population in the years from 2009 through 2013.

The chart below visualizes the age-adjusted mortality rate projected for each state in 2014 along with the actual mortality rate that was reported in 2014.

Collectively, there was very little difference in the average projected change in the age-adjusted mortality rate and the average actual mortality rate for the 26 states and the District of Columbia that chose to expand their Medicaid programs in 2014. The average actual rate was 0.2 deaths per 100,000 population higher than the projected decline based on the existing trend from 2009-2013, which is not significantly significant. If expanding the eligibility for Medicaid in these states produced life-saving benefits, you cannot tell the difference with this data.

The age-adjusted mortality rates in the 24 states that didn't expand their Medicaid welfare programs declined by 4.1 deaths per 100,000 population compared to what would have been expected in 2014 based on the preceding trends in these states from 2009 through 2013. We suspect that also is noise in the data.

These are interesting results, which if repeated again in both 2015 and 2016, would confirm that the expansion of Medicaid did very little to produce noticeable life-saving benefits for the Americans who were enrolled in it (one potential explanation for that result is presented here). With the single year of data we do have, it would appear that the Affordable Care Act's expansion of Medicaid provided very little benefit to the portion of the U.S. population that earns the lowest incomes outside of those falling below the poverty line in the jurisdictions where the expansion was implemented.

References

U.S. Centers for Disease Control. National Vital Statistics Reports. Volume 60. Number 3. Deaths: Final Data for 2009. Table 19. Number of deaths, death rates, and age-adjusted death rates for major causes of death: United States, each state, Puerto Rico, Guam, American Samoa, and Northern Marianas, 2009. [PDF Document]. 8 May 2013.

U.S. Centers for Disease Control. National Vital Statistics Reports. Volume 61. Number 4. Deaths: Final Data for 2010. Table 19. Number of deaths, death rates, and age-adjusted death rates for major causes of death: United States, each state, Puerto Rico, Guam, American Samoa, and Northern Marianas, 2010. [PDF Document]. 8 May 2013.

U.S. Centers for Disease Control. National Vital Statistics Reports. Volume 63. Number 3. Deaths: Final Data for 2011. Table 19. Number of deaths, death rates, and age-adjusted death rates for major causes of death: United States, each state, Puerto Rico, Guam, American Samoa, and Northern Marianas, 2011. [PDF Document]. 27 July 2015.

U.S. Centers for Disease Control. National Vital Statistics Reports. Volume 63. Number 9. Deaths: Final Data for 2012. Table 19. Number of deaths, death rates, and age-adjusted death rates for major causes of death: United States, each state, Puerto Rico, Guam, American Samoa, and Northern Marianas, 2012. [PDF Document]. 31 August 2015.

U.S. Centers for Disease Control. National Vital Statistics Reports. Volume 64. Number 2. Deaths: Final Data for 2013. Table 19. Number of deaths, death rates, and age-adjusted death rates for major causes of death: United States, each state, Puerto Rico, Guam, American Samoa, and Northern Marianas, 2013. [PDF Document]. 16 February 2016.

U.S. Centers for Disease Control. National Vital Statistics Reports. Volume 65. Number 4. Deaths: Final Data for 2014. Table 19. Number of deaths, death rates, and age-adjusted death rates for major causes of death: United States, each state, Puerto Rico, Guam, American Samoa, and Northern Marianas, 2014. [PDF Document]. 30 June 2016.

HealthPocket. Expansion of Medicaid in 2014. [Online Document]. 10 July 2014. Accessed 18 January 2017.

U.S. Census Bureau. Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2016 (NST-EST2016-01). [Excel Spreadsheet]. 7 December 2016. Accessed 18 January 2017.

Blase, Brian. New Gruber Study Raises Major Questions About Obamacare's Medicaid Expansion. Forbes. [Online Article]. 27 November 2016. Accessed 18 January 2017.