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. By giving people insurance, they argued, Obamacare could mitigate this problem.
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 poor and disabled. And Medicaid beneficiaries tend to visit the emergency room more often than the uninsured.
A January study of Medicaid beneficiaries in Oregon, published in the journal Science, finds that adult beneficiaries of the program rely on emergency rooms about 40 percent more than similar uninsured adults. The was study based on a randomized controlled trial in which a cohort of uninsured were selected by lottery to receive Medicaid, then compared against a control group of individuals who did not get coverage through the lottery. This was the first randomized study of Medicaid's effect on emergency room usage.
"When you cover the uninsured, emergency room use goes up by a large magnitude," Amy Finkelstein, a health economist at the Massachusetts Institute of Technology who served as a lead investigator on the study, said in a press statement accompanying the paper. 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," she said.