Medicaid + ER = Take a Number

By: Rachel Stewart
Wednesday, May 14, 2014

Traditionally, the emergency department has been a significant — and costly — source of medical care for people without health insurance. Some proponents of the Affordable Care Act (ACA) argue that its broader Medicaid coverage could reduce reliance on emergency rooms by making primary care more readily available. However, a new study in the journal Science suggests the expansion may make emergency rooms fuller.

Using research from the 2008 Oregon expansion program, in which 10,000 low-income adults became eligible for Medicaid through a lottery system, researchers found that emergency room visits among those covered were 40 percent higher than usage by a similar group who remained without Medicaid coverage. Thousands of residents flooded emergency rooms in 12 Portland-area hospitals in an 18-month period.

“For this particular paper, we are looking at emergency department use in around 25,000 individuals …,” says Sarah L. Taubman, ScD, Research Fellow at the National Bureau of Economic Research. “In our setting, the only differences between our control group and our treatment group are whether or not they were selected in the lottery and whether or not a random number was generated. So that allows us to identify the causal impact of Medicaid on these individuals.”

From Oregon’s 2008 adoption of the lottery system through 2011, overall emergency room visits in the state increased from 352 to 363 per 1,000 residents, according to the Henry J. Kaiser Family Foundation. That comports with national statistics provided by the CDC. Between 2001 and 2011, the CDC found that both children and adults with Medicaid were more likely to use the emergency room in the preceding year than their uninsured counterparts and those with private insurance. This is despite the fact that Medicaid covers primary care visits, which are generally less expensive than emergency care. Medicaid users typically visited the emergency room at least once annually during this 10-year period, according to the CDC.

What It Could Mean

Medicaid coverage is expected to continue to expand across the nation under the ACA. However, it may be too soon to say whether increased access to government-funded health coverage such as Medicaid will lead to increases in emergency room care overall. Taubman notes how unpredictable the findings of the Oregon study were.

“Emergency departments are so interesting because in this study people really thought it could go either way,” she says. “Some thought people would use more emergency care, and some thought they’d use all sorts of care that was more affordable.”