Most of the recent conversation about Medicaid expansion has been about costs. If states decide not to participate in Obamacare's expansion of Medicaid, how much will it save the federal government? If they do decide to participate, how much will it cost the states?
But what about the benefits? What happens when more people are eligible for Medicaid? I usually caution people not to focus too much on death rates when they look at questions like this, since mortality is notoriously hard to measure. What's more, the value of reliable medical care shows up far more in quality of life than it does in raw death rates. Decent dental care may not extend lifespans enough to show up in gross mortality statistics, but it's sure as hell still worthwhile for the folks who get to keep their teeth intact.
That said, preventing unnecessary deaths is still an important metric of decent access to medical care. So how does Medicaid stack up on this score? A trio of Harvard researchers tackled that question by looking at three states that expanded Medicaid eligibility between 2000 and 2005 (Arizona, Maine, and New York) and comparing their change in mortality rates with nearby states that didn't expand Medicaid eligibility. The chart below shows the results. In the expansion states, Medicaid enrollment went up dramatically, from 8% to 13% of the population. At the same time, mortality rates went down substantially, from 320 per 100,000 to 300 per 100,000.
As usual, you should interpret these results cautiously. Three states is a small sample, and the results are dominated heavily by strongly positive results in New York (in fact, mortality actually went up in Maine). Still, this study strongly suggest that Medicaid expansion really does extend lives. It's a helluva bargain for states that participate.