As we emerge from 18 months of pandemic operations, many emergency physicians are being asked how to prepare their emergency department for future patient needs. ED patient volumes have been at a steady increase since World War II. The American health care system will be on a different trajectory following this coronavirus pandemic and will see the growth of many virtual medical services for patient care.

When it comes to the data we can use to analyze ED trends and support planning for the future, the Centers for Disease Control and Prevention (CDC), American Hospital Association (AHA), and National Emergency Department Inventory (NEDI)-USA use different survey techniques and definitions of “emergency department.” I reviewed the four organizations that provide insight into the volume and nature of U.S. ED visits in our May 2020 issue.¹ Here’s a refresher.

The CDC just published the statistical survey of 2018 ED visits as part of the National Hospital Ambulatory Medical Care Survey (NHAMCS).² The NHAMCS provides the greatest insight into ED visit characteristics, with consistent data since 1992. Publication of the 2018 data provides insight into the patients most often served in American emergency departments, what medical conditions generated an ED visit, how patients were evaluated, and what disposition was made from the emergency department.

The AHA provides a data summary of community hospitals, which it defines as nonfederal, short-term general and other specialty hospitals. The AHA data simply count the number of ED visits reported, with a very consistent picture of volume increases in the first 18 years of this century.

The NEDI-USA database is maintained by the Emergency Medicine Network (EMNet) and contains data on all U.S. emergency departments and freestanding emergency departments. The inclusion of freestanding emergency departments makes the EMNet data the most comprehensive picture of patients seen in all sites in the United States referred to as emergency departments.

The 2001–2018 ED visit estimates from the CDC, AHA, and NEDI-USA are summarized in Figure 1.

The fourth organization producing data on ED performance measures is the ED Benchmarking Alliance (EDBA). The EDBA has just published the first report on 2020 data, which provides further insight into patient trends for future planning.

What Are the Trends in these Datasets?

• Since World War II, American emergency departments have served increasing numbers of visits each year, with 2020 seeing the first significant drop in ED volumes.
• Patients frequently served include demographic categories of infants, nursing home residents, the homeless, and Black persons.
• Because of the rapid increase in the number of senior citizens and their high utilization, that group fuels much of the year-over-year growth in ED visits. Persons over age 75 accounted for about 10 percent of ED visits, with about 600 visits per 1,000 population, in 2018.
• The ED population distribution features less injury and more illness, with only 27 percent of ED patients presenting with an injury.
• Patients are presenting to the emergency department with higher-acuity medical needs. A mere 3.1 percent of ED visits are classified as nonurgent, with the highest rates of these visits for patients under age 15. Babies under a year of age are among the highest utilization age groups at 1,006 ED visits per 1,000 population.
• Viewed through the lens of “presenting complaint,” stomach and abdominal pain were the most common, each resulting in around 9 percent of visits. At 5 percent, chest pain was next most common complaint.
• The largest group of patients being seen in the emergency department have Medicaid or CHIP insurance, at 41.3 percent of ED visits. Private insurance covers about 30.8 percent of ED visits, Medicare covers 19.3 percent, and people with no insurance account for 8.5 percent.
• There are growing numbers of patient visits related to primary mental health issues. For 2.7 million visits, a mental health professional saw the patient in the emergency department, and in about 1.6 million ED visits, the result was admission of the patient to the mental health unit of a hospital.
• The emergency department is a site of aggressive diagnostic testing and treatment. More patients are presenting with symptoms that raise issues about a cardiac etiology. About 22 percent of patient visits resulted in an ECG provided, and about 5.1 percent resulted in cardiac biomarkers being analyzed.
• Imaging was provided to about 51 percent of ED visits. The use of CT scanning was documented in 19.6 percent of visits, with about 42 percent of those CTs imaging the head.
• The 2018 CDC data estimate that about 23 million ED visits resulted in hospital admission or placement in an observation unit, for a 16 percent admission rate. The NHAMCS indicates that the average patient admitted through the emergency department stayed in the hospital 5.8 days. The ED admission rate has rapidly increased, and in 2020, the EDBA data found that about 21 percent of ED visits resulted in placement in an inpatient unit. That data survey found that roughly 69 percent of hospital inpatients were processed through the emergency department. The emergency department remained the front door to the hospital, even during the pandemic.
• A growing number of ED visits result in the patient being seen by physician assistants and nurse practitioners. In total, 35.3 million visits included services by physician assistants and/or nurse practitioners (27 percent of all ED patient visits); 16.4 million of those patients were not seen by a physician.
• Many patients have ongoing care provided in the emergency department. The CDC estimates that 6.4 percent of ED patient visits were for a follow-up visit and about 3.9 percent of patients had been seen an emergency department in the last 72 hours.

Planning for the Future of Emergency Care

The number of ED visits decreased in 2020 but is returning to pre-pandemic numbers this summer. Some low-acuity patient demand will decrease, and those patient needs will be served by other suppliers of acute, unscheduled care. The trends portrayed by NHAMCS through 2018 no doubt continued into 2021, with ED patients who are older and sicker and with needs for expedient diagnostic services and hospital admission.

The coronavirus pandemic put the emergency department clearly in the spotlight as the entity responsible for acute, unscheduled medical care. As such, the immediate future provides an opportunity for emergency physicians to trumpet the value of the emergency department to hospital and community leaders. But emergency departments must evolve to meet the needs of senior citizens, rapid diagnostics, mental health concerns, and, of course, hospital admissions.