Uninsured emergency department visits down after Medicaid expansion

Adapted from a Vanderbilt University Medical Center news release

Fewer uninsured patients are walking through the doors of emergency departments in states that expanded Medicaid coverage under the Affordable Care Act, even though the total number of visits has increased since 2014, according to an Annals of Emergency Medicine study released today.

Lead author Sayeh Nikpay, Ph.D., assistant professor of Health Policy at Vanderbilt University Medical Center and former fellow at the University of Michigan Institute for Healthcare Policy and Innovation, said the increase was “modest,” with 2.5 more emergency department visits per 1,000 people in states that expanded Medicaid coverage under the ACA.

Uninsured care for those patients decreased by 5.3 percent during that same period after 2014, she said.

“Our results suggest that the coverage part of the ACA Medicaid expansion is working,” Nikpay said. “People who need care can access care. However, it isn’t surprising that emergency department visits didn’t fall because even if you gained Medicaid coverage, the ACA did little to make primary care more accessible, for example, offering evening and weekend hours.”

Senior author Thomas Buchmueller, Ph.D., a professor in the U-M Ross School of Business, notes, "Although Michigan is not one of the states in the emergency department data that was used in this study, the main result -- a decline in uninsured patients and an increase in insured patients -- corresponds with what we have seen regarding inpatient admissions since the Healthy Michigan Plan was launched." (Read about the 2016 study of this issue, by an IHPI-based team.)

The study analyzed patient visits in 25 states — 14 that expanded Medicaid coverage and 11 that did not — and found the share of visits covered by private insurance remained constant for expansion states and increased by several percentage points for non-expansion states.

Gains in insurance coverage in non-expansion states were almost entirely in the form of private coverage, not Medicaid.

“Medicaid expansion had a larger impact on the health care system in places where more people were expected to gain coverage,” Nikpay said. “The share of emergency department visits covered by Medicaid increased by 8.8 percentage points in expansion states, as compared to non-expansion states.

“The change in total visits was twice as large in Kentucky, where most childless adults were ineligible for Medicaid at any income level before 2014, as compared to Hawaii, where childless adults were already eligible for Medicaid above the poverty line,” she said.

In addition to Nikpay, the paper's authors are Thomas Buchmueller, Ph.D., of the U-M Ross School of Business, Helen Levy, Ph.D. of the Institute for Social Research and Ford School of Public Policy, and Seth Freedman, Ph.D., a former Robert Wood Johnson scholar at U-M who is now at Indiana University.