Medicaid Expansion Reduced Emergency Department Visits by Low-income Adults Due to Barriers to Outpatient Care

BACKGROUND Prior studies have found conflicting effects of Medicaid expansion on emergency department (ED) utilization but have not studied the reasons patients go to EDs. OBJECTIVES Examine the changes in reasons for ED use associated with Medicaid expansion. RESEARCH DESIGN Difference-in-difference analysis. SUBJECTS We included sample adults from the 2012 to 2017 National Health Interview Survey who were US citizens and reported a total family income below 138% federal poverty level (n=30,259). MEASURES We examined changes in the proportion of study subjects reporting: (1) any ED visits; (2) ED visits due to perceived illness severity; (3) office not open; and (4) barriers to outpatient care, comparing expansion and nonexpansion states. RESULTS Overall, 30.6% of low-income adults reported ED use in the past year, of which 74.1% reported illness acuity, 12.4% reported office not open, 9.5% reported access barriers, and 4.0% did not report any reason. Medicaid expansion was not associated with statistically significant changes in overall ED use [-2.2% (95% confidence interval-CI), -5.5% to 1.2%), P=0.21], ED visits due to perceived illness severity [0.5% (95% CI, -2.4% to 3.5%), P=0.73], or office not open [-0.9% (95% CI, -2.3% to 0.5%); P=0.22], but was associated with significant decrease in ED visits due to access barriers [-1.4% (95% CI, -2.6% to -0.2%), P=0.022]. CONCLUSIONS Medicaid expansion was associated with a decrease in low-income adults who reported outpatient care barriers as reasons for ED visits. There were no significant changes in overall ED utilization, likely because the majority of respondent reported ED use due to concerns with illness severity or outpatient office was closed.