California emergency department visit rates for medical conditions increased while visit rates for injuries fell, 2005-11.

The emergency department (ED) is the source of most hospital admissions; provides care for patients with no other point of access to the health care system; receives advanced care referrals from primary care physicians; and provides surveillance data on injuries, infectious diseases, violence, and adverse drug events. Understanding the changes in the profile of disease in the ED can inform emergency services administration and planning and can provide insight into the public's health. We analyzed the trends in the diagnoses seen in California EDs from 2005 to 2011, finding that while the ED visit rate for injuries decreased by 0.7 percent, the rate of ED visits for noninjury diagnoses rose 13.4 percent. We also found a rise in symptom-related diagnoses, such as abdominal pain, along with nervous system disorders, gastrointestinal disease, and mental illness. These trends point out the increasing importance of EDs in providing care for complex medical cases, as well as the changing nature of illness in the population needing immediate medical attention.