Medicaid Coverage Boosts Emergency Department Visits, Study Finds

Oregon's 2008 Medicaid expansion increased emergency department use, according to a new study. ( Image: jkbowers/

Oregon’s 2008 Medicaid expansion increased emergency department use, according to a new study. ( Image: jkbowers/

A limited Medicaid expansion in Oregon did not channel adults away from expensive emergency department care, according to a new study. In fact, the data show just the opposite: eligible adults chosen in a lottery to receive Medicaid coverage used emergency departments about 40% more often than those who weren’t selected.

Published online today in the journal Science, the study examined emergency department records for about 25 000 adults—nearly 10 000 who were picked randomly in the 2008 lottery and some       15 000 who were not chosen. During an 18-month period beginning in March 2008, the investigators found that the lottery winners were 7% more likely than those not chosen to seek care in an emergency department. The lottery winners made 0.41 more emergency visits per person during the study period, a 40% increase over the average 1.02 visits per person by the adults not picked in the lottery.

The increased emergency department visits were solely for outpatient care, according to the findings. Some of the most pronounced increases were for conditions such as chronic illnesses that could be treated in primary care offices.

The issue is salient as many states begin to expand their Medicaid programs through provisions in the Affordable Care Act. The study authors noted that because Medicaid expansions decrease out-of-pocket costs for emergency department visits, Medicaid enrollees may be expected to use them more often. Or, as some policy makers have argued, increased Medicaid coverage should be expected to decrease emergency department visits because coverage affords greater access to primary care services.

Some limitations of the study make it difficult to generalize the findings to other settings, the authors noted. The study sample, primarily in the Portland, Oregon, area, was predominantly white individuals living in an urban region. Adults in the study didn’t face a mandate; they voluntarily signed up for coverage. Also, people in the study gained an average 13 months of coverage, so longer-term results may differ.

The investigators wrote that, based on an average emergency department visit cost of $435, Medicaid coverage may increase annual spending in emergency departments by about $120 per covered individual.

Categories: Caring for the Uninsured and Underinsured, Emergency Medicine, Health Policy, Primary Care/Family Medicine, Public Health