What accounts for differences in the use of hospital emergency departments across U.S. communities?

Increases in the use of hospital emergency departments (EDs) might contribute to crowding at some EDs, higher health care costs, and lower-quality primary care. This study examines the extent to which differences in populations and health system factors account for variations in ED use across U.S. communities. Contrary to popular perceptions, communities with high ED use have fewer numbers of uninsured, Hispanic, and noncitizen residents. Outpatient capacity constraints also contribute to high ED use. However, high ED use in some communities also likely reflects generic preferences for EDs as a source of care for nonurgent problems.