A new study published in the New England Journal of Medicine adds to the relatively sparse body of knowledge regarding the impact of Medicaid on adults’ health. Researchers looked at three states, Maine, New York, and Arizona that made Medicaid available to childless adults between 2000 and 2005 and found a net decrease in mortality of 6.1 percent.  When adjusting for demographic variables, older adults (those between the ages of 35 and 64), minorities, and residents of poor counties experienced the greatest declines in mortality.

These states experienced a net decrease of almost 15 percent in its uninsured rates, seen in both those below and above 200 percent of the federal poverty line (FPL). Medicaid coverage increased by almost  25 percent, which was concentrated among low-income adults.  Coverage gains also translated to better use of the health care system: states saw a marked decrease in the number of people who delayed care due to costs, as well as an increase in self-reported “excellent” or “very good” health.

How did the study arrive at these findings? Researchers examined the mortality rates for adults in the three states, for the five years before and after their expansions. Each expansion state was compared to a non-expansion state (or states) with which it shares a border and similar demographic characteristics to assess whether the expansions were associated with changes in mortality and other health related measures.

Despite the fact that the study doesn’t show a causal relationship between access to Medicaid coverage and lower mortality rates, its findings are consistent with the limited research on the topic (including the preliminary findings from the ongoing Oregon study) that shows Medicaid is good for your health.

As state policy makers consider the Medicaid expansion under the ACA, let’s hope they take into account the health implications for the most vulnerable.

Note: The New England Journal of Medicine can only be accessed via subscription, but you can read a more-in depth New York Times piece on the study.