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Impact of Policy Changes on Emergency Department Use by Medicaid Enrollees in Oregon

Lowe, Robert A. MD, MPH*†‡§¶∥; Fu, Rongwei PhD*†‡; Gallia, Charles A. PhD**

doi: 10.1097/MLR.0b013e3181dbddb1
Original Article

Objective: In 2003, Oregon's Medicaid expansion program, the Oregon Health Plan (OHP), implemented premiums and copayments and eliminated outpatient behavioral health services. We ascertained whether these changes, including $50 copayments for emergency department (ED) visits, affected ED use.

Methods: This study used statewide administrative data on 414,009 adult OHP enrollees to compare ED utilization rates (adjusted for patient characteristics) in 3 time periods: (1) before the cutbacks, (2) after the cutbacks, and (3) after partial restoration of benefits. We examined overall ED visits and several subsets of ED visits: visits requiring hospital admission, injury-related, drug-related, alcohol-related, and other psychiatric visits. Because the policy changes affected only the expansion program (OHP Standard), we ascertained the impact of these changes compared with a control group of categorically eligible Medicaid enrollees (OHP Plus).

Results: Compared with the control group, case-mix-adjusted ED utilization rates fell 18% among OHP Standard enrollees after the cutbacks. The rate of ED visits leading to hospitalization fell 24%. Injury-related visits and psychiatric visits excluding chemical dependency exhibited a similar pattern to overall ED visits. Drug-related ED visits increased 32% in the control group, perhaps reflecting the closure of drug treatment programs after the cutbacks reduced their revenue.

Conclusion: The policy changes were followed by a substantial reduction in ED use. That ED visits requiring hospital admission fell to about the same extent as overall ED use suggests that OHP enrollees may have been discouraged from using EDs for emergencies as well as less-serious problems.


From the *Department of Emergency Medicine, †Center for Policy and Research in Emergency Medicine, ‡Department of Public Health and Preventive Medicine, and §Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR; ¶Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA; ∥Emergency Medicine Network (EMNet), Boston, MA; and **State of Oregon, Division of Medical Assistance Programs, Salem, OR.

Supported by the Office for Oregon Health Policy and Research through grants from the Robert Wood Johnson Foundation State Coverage Initiatives and the Robert Wood Johnson Foundation Changes in Health Care Financing and Organization Initiative, and by a Riggs Family/Emergency Medicine Foundation Health Policy Research Grant.

Earlier results from this study were presented at the American College of Emergency Physicians Research Forum, September 2005, Washington, DC.

Reprints: Robert A. Lowe, MD, MPH, Center for Policy and Research in Emergency Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Mail Code CR114, Portland, OR 97239–3098. E-mail:

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© 2010 Lippincott Williams & Wilkins, Inc.