Costs of ED episodes of care in the United States.

BACKGROUND: Emergency department (ED) care is a focus of cost reduction efforts. Costs for acute care originating in the ED, including outpatient and inpatient encounters (i.e. ED episodes), have not been estimated.
OBJECTIVE: We estimate total US costs of ED episodes, potentially avoidable costs, and proportional costs of national health expenditures (NHEs).
METHODS: We conducted a secondary analysis of 2010 data from the Medical Expenditure Panel Survey, National Hospital Ambulatory Medical Care Survey, and the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample. Outpatient ED encounters were categorized based on the New York University algorithm and admissions by ambulatory care-sensitive condition (ACSC) vs non-ACSC. Potentially avoidable encounters were nonemergent ED visits and ACSC hospital admissions. Using the Medical Expenditure Panel Survey, we determined mean per-visit payments for each visit type. Using the National Hospital Ambulatory Medical Care Survey and Nationwide Inpatient Sample, we estimated aggregate expenditures and proportional costs of NHE by visit category.
RESULTS: Emergency department episodes of care accounted for $328.1 billion in payments in 2010. This represented 12.5% of NHE; ED admissions were 8.3% and outpatient ED care was 4.2%. Nonemergent outpatient visits were the most common, comprising 30.4% of ED episodes, and non-ACSC admissions were the most costly at $188.3 billion. Potentially avoidable encounters accounted for $64.4 billion, 19.6% of ED episodes, and 2.4% of NHE.
CONCLUSIONS: More than 1 in 10 health care dollars is spent on ED episodes of care. Of this, less than 1 in 5 dollars is potentially avoidable; therefore, efforts to reduce ED visits through improved primary care may have little impact on overall costs.