Peter Suderman at Hit and Run:

Supporters of Obamacare have long pitched the law as a way to address emergency room crowding caused by lack of health coverage. Individuals without health coverage, the thinking goes, have no place to turn when they need medical attention, and as a result they head to the emergency room. That creates crowding, which can strain medical resources. It's also more expensive than an ordinary trip to the doctor. The theory was that by giving people insurance, Obamacare could mitigate this problem, allowing more people to skip emergency care facilities by relying on less crowded, less expensive doctors offices instead.

President Obama pitched a version of this idea in a speech last September, arguing that emergency room visits by the uninsured represented a hidden tax on everyone else. "When uninsured people who can afford to get health insurance don't, and then they get sick or they get hit by a car, and they show up at the emergency room, who do you think pays for that?" he asked.

o...Obamacare to the rescue, right?

Not exactly:

But the best evidence has never really supported the hope that the law would reduce emergency room usage. That's because much of the law's expanded coverage comes via Medicaid, the jointly run federal-state program for the low income and disabled. And Medicaid beneficiaries tend to visit the emergency room more often than the uninsured.

A new study of Medicaid beneficiaries in Oregon makes a strong version of this case. The study, published today in the journal Science, finds that adult Medicaid beneficiaries rely on emergency rooms about 40 percent more than similar uninsured adults.

"When you cover the uninsured, emergency room use goes up by a large magnitude," said Amy Finkelstein, a health economist at the Massachusetts Institute of Technology who served as a lead investigator on the study, in an MIT press statement accompanying the study.

There were no exceptions to the trend. "In no case were we able to find any subpopulations, or type of conditions, for which Medicaid caused a significant decrease in emergency department use," said Finkelstein.

"No case"? Obamacare is about to expand Medicaid by 3-4 million patients, nearly half of whom will be crowding into already crowded emergency rooms.

It was delusionsal to think otherwise. Medicaid recipients tend to live in areas ill served by health care facilities - few hospitals, clinics, or even doctors' offices. Where did they expect these people to go? Going to the emergency room because you have the sniffles, or an ear ache is a gigantic waste of resources. And it puts the rest of us at risk when ER's are overwhelmed with patients who aren't in need of emergency treatment.

Suderman points out that there is no corresponding improvement in health as a result of Medicaid expansion:

Which means that Medicaid is mostly a way of insulating beneficiaries from financial shock, at the cost of more crowded emergency rooms and greater utilization of health care resources.

It's not so much a health program as a financial buffer--and a costly one at that.

Indeed. And another Obamacare myth bites the dust.