Studies show that EMS delivers a significant percentage of patients who will go on to be admitted. Armed with these numbers, we must rethink diversion, considering its true cost to the hospital.
Hard data can tell us some essential things about the emergency department story, from resource utilization to management trends. In 2012, the ED Benchmarking Alliance gathering data from more than 1,000 participating hospitals, and the results were illuminating to say the least. This month we examine the data that reveals a significant correlation between ambulance transports and ED visits that lead to hospital admission.
Specifically, the EDBA survey asked member EDs to report the percentage of patients that arrive by EMS, and those that arrive by EMS and are admitted from the ED to the hospital. For the year 2012, about 16% of patients seen in the ED arrive by EMS, and more than 40% of those EMS patients are admitted (Table 1). This percentage has been very consistent over the last nine years. But there is significant variation between the ED volume cohorts. EMS arrival rates are higher in those EDs with larger volumes, and by far highest in EDs serving adults, where about 23% of their patients arrive in an ambulance. Those EDs over 40K volume see about 19% of their patients arrive by EMS, and there are a number of those EDs with EMS arrivals over 30%. Ambulance arrival rates hover around 12% in smaller volume EDs, and about 8% in EDs that serve a primarily pediatric patient population.
The percentage of patients arriving in an ambulance predicts the percentage of ED admissions to the hospital, as illustrated in Table 1.
Column one and column three of this table demonstrate a high level of correlation.
Available data indicate that population utilization of ambulances is around 100 times per 1000 persons in a service area. Utilization of EMS in communities, and the characteristics of EMS patients, are not widely reported. There is a terribly inaccurate myth that EMS patients are persons just looking for a free ride to the clinic, or for a quicker pathway to an ED bed. The most common symptoms resulting in an EMS transport are the following:
- Chest symptoms, and those relating to Acute Coronary Syndrome (ACS) presentations
- Shortness of breath
- Injury requiring packaging of some type
- Altered level of consciousness
- Abdominal discomfort
How much Should the Hospital Spend to Avoid EMS Diversion?
In America’s current health care market, hospitals survive on revenue from inpatient service, and patients admitted through the ED are major contributors to that revenue stream. EMS transports many of those more critical patients to the hospital, where emergency physicians then make critical patient decisions about admission, transfer or outpatient care.
The cost of diversion, therefore, is very significant. To calculate the cost, one might count the average number of EMS patients arriving during the busy hours of the day (not including the middle of the night, when diversion rarely is utilized). Assume that arrival rate is a modest two EMS patients per hour. Count the average revenue for ED services for those patients for the hospital. Many hospitals use a direct revenue per patient of $500. Calculate the average rate of admission for arriving EMS patients. In the EDBA survey, it is 40%. Calculate the average contribution to overhead for a patient that is admitted. Many financial officers report that an admitted patient contributes $6000 above the direct cost of service. If that is the case, every 10 patients diverted costs the hospital 4 admissions, or $24,000. Calculating an economic loss for 10 patients then equals: $500 times 6 patients ($3000) plus $24,000 for admissions, totaling $27,000, or $2700 per patient. So the cost of an hour of diversion for an ED that greets two EMS patients per diversion hour is $5400. This is direct revenue loss only, not the loss of the patient for future visits and admissions, and loss of relationship with EMS.
One could speculate that ED crowding and diversion are increasing the acuity of EMS patients. The diversion process causes some EMS providers to advise lower acuity patients to go to the ED by private vehicle, so they can select the hospital of their choice. The remaining EMS patients would be more likely to have high acuity needs, and require hospital admission. It is also notable that communities having extensive networks of urgent care centers have EMS patients that are more likely to be admitted.
Emergency Medical Services are a valued partner to hospitals and their emergency departments. EMS patients are much more likely to need higher levels of ED service, and to be admitted to the hospital. Diversion of EMS due to ED crowding, which often results from boarding of admitted patients in the ED, is costly to the hospital, and causes long term damage to the relationship of the hospital with EMS providers and the community.
Dr. Augustine is the vice president of the Emergency Department Benchmarking Alliance and is the Director of Clinical Operations for Emergency Medicine Physicians (EMP) in Canton, Ohio.
Burt CW, McCaig LF, Valverde RH. Analysis of ambulance transports and diversions among U.S. emergency departments. Ann Emerg Med 2006;47:317--26.