Trends in the Contribution of Emergency Departments to the Provision of Hospital-Associated Health Care in the USA.

Traditional approaches to assessing the health of populations focus on the use of primary care and the delivery of care through patient-centered homes, managed care resources, and accountable care organizations. The use of emergency departments (EDs) has largely not been given consideration in these models. Our study aimed to determine the contribution of EDs to the health care received by Americans between 1996 and 2010 and to compare it with the contribution of outpatient and inpatient services using National Hospital Ambulatory Medical Care Survey and National Hospital Discharge Survey databases. We found that EDs contributed an average of 47.7% of the hospital-associated medical care delivered in the United States, and this percentage increased steadily over the 14-year study period. EDs are a major source of medical care in the United States, especially for vulnerable populations, and this contribution increased throughout the study period. Including emergency care within health reform and population health efforts would prove valuable to supporting the health of the nation.