Trends in Adult Emergency Department Visits in California by Insurance Status, 2005-2010

To the Editor: Emergency department (ED) use has been affected by insurance patterns over time and will likely be further affected by health reform’s expansions of coverage. Because of their disproportionate use of the ED, uninsured patients are often impugned as high, and frequently inappropriate, ED users.1,2 However, recent studies have shown that insured patients can be more frequent utilizers than the uninsured, particularly those with insurance like Medicaid that still leaves them with difficulties in accessing primary care.2-4 We therefore sought to describe recent trends in the association between insurance coverage and ED use in California for non-elderly adult patients, who have experienced the greatest changes in insurance coverage in recent years and are likely to see the biggest shifts as the result of health reform. Previous studies have considered trends in ED use, but predate the recent economic downturn and related insurance changes.2,5