I've written at length about the negative effects of expanding a broken Medicaid program under Obamacare. Poor health outcomes and limited care access rank high among the reasons to be wary of throwing more money at the program, but consider also this broken promise of the law: that by expanding the program, supposedly wasteful emergency room visits would fall, because more people would be "covered" by a government health plan. But fresh research from the New England Journal of Medicine shows that those ER claims have not been justified: rather than decrease unnecessary ER visits, Medicaid expansion actually appears to increase them.

The new study resulted from the Oregon Medicaid experiment, in which Oregon expanded Medicaid to a limited number of lower-income, non-disabled adults using a lottery. The expansion's design, which involved random assignment, allowed researchers to draw more reliable conclusions about the impact of Medicaid eligibility than observational studies.

. . . Of crucial importance, the study also found that "[a]cross a variety of alternative specifications, we consistently find that Medicaid's value to recipients is lower than the government's costs of the program, and usually substantially below." They estimated that the "benefit to recipients from Medicaid per dollar of government spending range from about $.2 to $.4."

Cato director of health policy studies Michael Cannon has said that the Oregon Health Insurance Experiment (OHIE) "may be the most important study ever conducted on health insurance," precisely because researchers were able to isolate the health effects of Medicaid coverage in ways that, under normal research circumstances, is very difficult to do. These findings, then, represent a gold standard by which claims about the Medicaid program can be fact checked in key respects, including emergency room usage.

In our direct primary care paper, published last year, we looked at emergency room usage and Medicaid as well, and we found plenty of evidence to support the OHIE research team's findings.

Perhaps most startling is recent news from a survey of emergency room doctors, taken this year by the American College of Emergency Physicians [ACEP], suggesting that the expansion of Medicaid has actually increased—not decreased or kept flat—emergency room usage. As explained by Dr. Howard Mell of the ACEP in the Wall Street Journal, "Visits are going up despite the ACA, and in a lot of cases because of it."

ACEP's 2015 report was not the product of a once-off survey, either. In 2014, one-third of emergency departments reported seeing more Medicaid patients; in 2015, over half reported an increase.

With the failures of the Obamacare exchanges, it is more important than ever to ensure that Missourians are not exposed to more of the Obamacare disaster. That means continuing to reject a broken Medicaid expansion that doubles down on bad policy. Without reform, the Medicaid program will continue to imperil both the health of patients and the money of taxpayers, and unfortunately, expanding Medicaid would serve to aggravate the program's long-standing problems.