Study examines short-term impact of Medicaid expansion, insurance status on ED use

The 2014 expansion of Medicaid under the Affordable Care Act (ACA) has led to changes in insurance status and ED utilization that suggest greater choice of hospital facilities for patients and higher ED usage by insured patients, according to a new study.

Researchers performed a quasi-experimental observational study from 2012 to 2014 of uninsured and Medicaid-insured adults 18 to 64 years of age who received care at 126 investor-owned, hospital-based EDs. Data measured were number of ED visits, type of visits, and average travel time to the ED. The authors performed interrupted time-series analyses comparing changes from the end of 2013 to the end of 2014 in patients from states that expanded Medicaid in January 2014 and patients from those that did not. The study results were published online Dec. 20 by Annals of Internal Medicine.

In the 17 states in the study that expanded Medicaid and the 19 states that did not, 1.06 million and 7.87 million ED visits took place during the study period, respectively. After 12 months of ACA expansion, uninsured visits in the EDs in Medicaid expansion states decreased by 47.1% (95% CI, −65.0% to −29.3%) versus 5.3% (95% CI, −24.0% to 13.6%) in nonexpansion states. Medicaid ED visits, meanwhile, increased by 125.7% (95% CI, 89.2% to 162.6%) versus 11.4% (95% CI, −43.6% to 51.3%) in nonexpansion states. ED visits for nonemergent conditions decreased by 43.9% (95% CI, −54.5% to −33.3%) in uninsured patients and increased by 129.7% (95% CI, 94.2% to 165.7%) in Medicaid patients after Medicaid expansion. Medicaid visits for emergent conditions that could be treated in primary care increased by 146.9% (95% CI, 108.9% to 185.4%) in expansion states and decreased by 7.2% (95% CI, −48.0% to 49.6%) in nonexpansion states. Distance traveled for ED visits involving nondiscretionary conditions that required immediate medical care decreased by 6.2% (95% CI, −8.9% to −5.3%) in all Medicaid patients in expansion states and by 0.1% (95% CI, −7.3% to −7.1%) in nonexpansion states.

The authors acknowledged that they looked only at for-profit, investor-owned facilities and that their results may not be generalizable to other hospital types. However, they concluded that based on their findings, insurance status and location and type of ED visits appear to have changed significantly during the first year of Medicaid expansion under the ACA, providing patients with more care choices. The authors noted that more research over a longer time period and at a broader sample of hospitals is needed but said that their results “provide an important new context for the ongoing debate over the ACA's effect on access to hospital care.”