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.

Overall, the authors estimated 10 additional ED visits per 1,000 people. As predicted, Medicaid expansion resulted in more visits by patients with Medicaid. The proportion of visits covered by Medicaid increased from 35 percent pre-ACA to 48 percent during the study. The authors argue that some of this increase may be temporarily caused by pent-up demand from patients who needed health care but could not afford it prior to the ACA. A reciprocal decrease in the proportion of uninsured visits was noted (from 23 percent down to 11 percent).

Further analyzing the data provides interesting insights into the chief complaints that became more common for patients with Medicaid. The largest increases were for dental and mental health visits, which aligns with the disproportionate number of Medicaid-eligible patients who report less than excellent mental health.¹⁰

Naturally, increased visits raise questions about the effects on emergency departments. Without an increase in capacity, more visits may mean overcrowding, decreased quality of care, and worse patient outcomes. Changes in payer mix affect the hospital’s bottom line, since Medicaid generally reimburses less than private insurance. However, Medicaid reimbursement is higher than that from self-pay patients. Furthermore, recognizing that there are fewer uninsured patients, the ACA reduces payments for hospitals serving a disproportionately high level of uninsured patients.¹¹ The balance of these clinical and financial forces should continue to be explored.

Dr. Dark is assistant professor of emergency medicine at Baylor College of Medicine in Houston and executive editor of Policy Prescriptions.

Dr. Maughan is an emergency medicine resident at Maine Medical Center in Portland, Maine.

Dr. Sontag is an emergency medicine resident at UT Health San Antonio.

References

1. Miller S. The effect of insurance on emergency room visits: an analysis of the 2006 Massachusetts health reform. J Public Econ. 2012;96:893-908.
2. ACEP. ER visits continue to rise since implementation of Affordable Care Act. ACEP website. Accessed March 23, 2018.
3. Dresden SM, Powell ES, Kang R, et al. Increased emergency department use in Illinois after implementation of the Patient Protection and Affordable Care Act. Ann Emerg Med. 2017;69(2):172-180.
4. Taubman SL, Allen HL, Wright BJ, et al. Medicaid increases emergency-department use: evidence from Oregon’s health insurance experiment. Science. 2014;343(6168):263-268.
5. Chalmers N, Grover J, Compton R. After Medicaid expansion in Kentucky, use of hospital emergency departments for dental conditions increased. Health Aff (Millwood). 2016;35(12):2268-2276.
6. Colorado Hospital Association Center for Health Information and Data Analytics. Impact of Medicaid expansion on hospitals: updated for second-quarter 2014. C Colorado Hospital Association website. Accessed March 23, 2018.
7. Bradley CJ, Gandhi SO, Neumark D, et al. Lessons for coverage expansion: a Virginia primary care program for the uninsured reduced utilization and cut costs. Health Aff (Millwood). 2012;31(2):350-359.
8. Finkelstein AN, Taubman SL, Allen HL, et al. Effect of Medicaid coverage on ED use – further evidence from Oregon‘s experiment. N Engl J Med. 2016;375(16):1505-1507.
9. Nikpay S, Freedman S, Levy H, et al. Effect of the Affordable Care Act Medicaid expansion on emergency department visits: evidence from state-level emergency department datases. Ann Emerg Med. 2017;70(2):215-225.
10. Newport F. Strong relationship between income and mental health. Gallup web site. Accessed March 23, 2018.
11. Medicaid and CHIP Payment and Access Commission. Report to Congress on Medicaid disproportionate share hospital payments. MACPAC website. Accessed March 23, 2018.