Emergency physicians and emergency department leaders face an important time in determining how to serve the needs of their communities in a changing health system. The trends that have driven the growth of emergency care have not been altered by government or payer policies to date. The National Hospital Ambulatory Medical Care Survey (NHAMCS) by the Centers for Disease Control and Prevention (CDC) has detailed a continual increase in ED visits since at least 1992, as have data from the Emergency Department Benchmarking Alliance (EDBA), and it is confirmed in the operations reports for most of the 5,000 or so emergency departments in the country.
The 1992 NHAMCS Emergency Department Summary estimated that 89.8 million ED visits were made, or about 357 visits per 1,000 population. Injuries in those years were the cause of about 40 percent of the visits. In 2012, visits had grown to 131 million, which calculates to 424 visits per 1,000 population.1 Injuries accounted for 28 percent of ED visits, with the highest injury rates in persons age 75 and older. Continuing a 2.4 percent growth rate means that 150 million persons visited American emergency departments in calendar year 2016.
Most important in predicting ED utilization, staffing, design, and processes are the types of patients visiting the emergency department. The ED population is aging, which is consistent with the demographics of the country. Those persons age 75 and older in 1992 had 558 visits per 1,000 population. In 2011, that number increased to 682 visits per 1,000 population. Similarly, in those persons ages 65 to 74, the utilization increased from 314 to 369. These are the fastest-growing demographics in the country and will continue to grow for the next 20 years.
The EDBA has worked collaboratively with the CDC in producing useful data reports, which are needed for future planning. The EDBA hosted three summits that developed the definitions for the industry, the latest being published and used in the annual EDBA survey.2 EDBA trends in the last 12 years are summarized in Table 1.
The EDBA data show a reduction in the mix of young patients (defined as under age 18), from about 22 percent to about 16 percent over the last 10 years. Ambulance transportation is a stable source of about 16 percent of ED patients, with patients arriving in this manner being admitted around 39 percent of the time. For the sicker or seriously injured patients arriving in the emergency department, the admission rate over the last 10 years is stable between 16 percent and 18 percent.
The increasing age and medical complexity of ED patients result in measurable trends in the utilization of diagnostic testing that mirror those in the CDC reports. The use of CT scanning appears to have reached a high of 22 procedures per 100 patients, but MRI and other special imaging procedures like ultrasound are used at an increasing rate. The other diagnostic tool that is increasing in ED use is the 12-lead ECG. From 2004 to 2015, ECG utilization increased from 17 uses per 100 patients to 26 uses. This trend is likely to continue.
There is a continuing growth in the percentage of overall hospital admissions through the ED. The EDBA data survey over the last five years finds that between 65 percent and 68 percent of hospital inpatients are processed through the emergency department. This reflects the role of the emergency department as the “front door” to the inpatient unit.
The increasing age and medical complexity of ED patients result in measurable trends in the utilization of diagnostic testing that mirror those in the CDC reports.
There is a tremendous effort by many ED leaders to increase the flow of patients. ED providers have the greatest control over the flow of patients who are evaluated, treated, and released for outpatient follow-up. This represents more than 80 percent of the patients seen in American emergency departments. Despite increasing volumes and increasing age and acuity of patients over the past 11 years, the flow of patients has improved. For all patients, the door-to-provider time has decreased from more than 40 minutes to about 28 minutes (the 2012 NHAMCS study reports this number is 22 minutes). Overall median length of stay for the complete spectrum of ED patients has decreased about 15 minutes, from about 190 minutes to about 175 minutes. Patients treated and released from the emergency department have been processed an average of 10 minutes faster than 11 years ago, from 160 minutes to about 150 minutes. The flow improvements in the setting of increased volume have resulted in an overall reduction in ED patient walkaways, from more than 3 percent to about 2.6 percent.
The data from the CDC and from the EDBA indicate that the emergency department is an important and valuable component of the health system, providing unscheduled care to an increasing number of patients over the last 24 years.
Summary Talking Points from NHMACS and EDBA Data
- The CDC NHAMCS study started in 1992 documents that American emergency departments are seeing about 2.4 percent more visits every year.
- More patients arrive with medical illnesses rather than injuries.
- More patients are elderly and arrive by EMS.
- Despite increasing volumes and acuity, ED flow improvement has occurred.
- There is a continued increase in the use of ECGs, MRI scans, and ultrasound in the diagnostic workup of ED patients.
- The admission rate is stable over the last decade, at about 16 percent to 18 percent, and those patients represent about two-thirds of inpatient admissions to American hospitals.
- National Hospital Ambulatory Medical Care Survey: 2012 Emergency Department Summary Tables. CDC website.
- Wiler JL, Welch S, Pines J, et al. Emergency department performance measures update: proceedings of the 2014 Emergency Department Benchmarking Alliance consensus summit. Acad Emerg Med. 2015;22(5):542-553.