Will increasing access to health insurance decrease ED utilization by increasing access to primary care providers (PCPs)? On the other hand, does having health insurance make people more likely to visit the emergency department? These questions have important implications for ED capacity, quality of care, and future funding models.

When the Affordable Care Act (ACA) became law, differing opinions emerged about how it might affect ED utilization. Some argued that more insured patients would lead to better access to outpatient care, reducing the need for emergency care, as was seen in Massachusetts following the pre-ACA rollout of their own state’s health insurance expansion (Romneycare).¹ Others contended that more access to care would mean more usage of all types of care, resulting in increased ED visits, as 75 percent of emergency physicians believe.²

ED Usage in Illinois

A recent study, an analysis of ED use before and after Affordable Care Act (ACA) implementation in Illinois, provides evidence against the assumption that ED use would decrease as newly-insured patients received care from PCPs instead of the emergency department, leading to more efficient and less costly health care.³ The authors analyzed ED visits across Illinois from 2011 to 2015, comprising 36 months prior to and 24 months following ACA implementation. Although the number of ED visits by uninsured patients dropped, visits by Medicaid and private insurance patients increased more substantially, leading overall to a 5.7 percent increase in ED usage. Meanwhile, visit acuity appeared to remain constant, as the number of hospitalizations through the emergency department was essentially unchanged throughout the study period.

This study indicates that increasing access to insurance alone does not lead to a decrease in ED visits, and similar results have been found in Massachusetts, Oregon, Kentucky, and Colorado.^4-6 A program in Virginia offers an interesting alternative where, in addition to receiving health care, patients were assigned to PCPs.⁷ Although these PCPs were paid at rates higher than those offered by Medicaid, cost per patient had decreased significantly after three years of the program.

These potentially counterintuitive results highlight the complexity of health care reform. While providing health insurance may lead to fewer ED visits for some patients (ie, young adults), that effect does not hold universally. Of course, this immediate increase in ED use may be an anomaly in a long-term trend toward less ED use, though studies from Oregon have shown this effect to be long lasting.⁸ Additionally, there may be benefits to health insurance (ie, financial security, increased PCP visits, or potentially improved overall health) that are not captured in this study. However, while removing financial barriers to receiving care is likely an important part of reforming our health care system, this study indicates that health insurance expansion alone is unlikely to lead to more efficient health care delivery through reduced ED usage.

ED Utilization Trends

Another study investigated changes in ED utilization rates at a national level based on the hypothesis that increases in Medicaid-covered populations would result in proportional increases in ED visits.⁹ They also predicted a change in the payer mix that would result in fewer uninsured visits and more Medicaid-covered visits. States that opted not to expand Medicare coverage under the ACA served as the control group.