Prolonged ED wait time is associated with poor clinical outcomes

Nov 10 2009

One in four emergency department patients in 2006 waited longer to be evaluated by a clinician than recommended at triage, an increase from one in five in 1997, according to a report in the November 9 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

"Prolonged emergency department (ED) wait time decreases patient satisfaction, limits access, increases the number of patients who leave before being seen and is associated with clinically significant delays in care for patients with pneumonia, cardiac symptoms and abdominal pain," the authors write as background information in the article. Previous analyses have noted an increase in the amount of time ED patients wait to see a clinician. Between 1997 and 2004, median wait times increased 36 percent, from 22 minutes to 30 minutes. However, wait time alone is an imperfect measure of the timeliness of emergency care because it does not take into account the nature of patients' illnesses or injuries.

Leora I. Horwitz, M.D., M.H.S., of Yale-New Haven Hospital and Yale University School of Medicine, New Haven, Conn., and Elizabeth H. Bradley, Ph.D., also of Yale University School of Medicine, analyzed data from the National Hospital Ambulatory and Medical Care Survey to examine trends in the percentage of patients seen within the target time recommended during triage (initial process of prioritizing patients for treatment according to the seriousness of their condition). "Emergency departments are increasingly overcrowded, thereby straining resources," the authors write. "Triage assessment is intended to mitigate this strain by ensuring that the most acutely ill patients are prioritized for assessment, regardless of the competing demands on ED physicians' time. Considering wait time within the clinical context of triage assessment therefore allows for a more nuanced understanding of the timeliness of ED care than wait time in aggregate."

A total of 151,999 ED visits between 1997 and 2006 were categorized in the database as emergent (recommended that clinicians see in zero to 14 minutes), urgent (see in 15 minutes to 60 minutes), semi-urgent (see in 61 minutes to two hours) or non-urgent (see in more than two to 24 hours).

For all categories, the percentage of patients seen within the triage target time declined an average of 0.8 percent per year, from 80 percent in 1997 to 75.9 percent in 2006. The decline was greater—2.3 percent per year—for emergent patients, who had 87 percent lower odds than semi-urgent patients of being seen within the triage target time. "Overall, 56.6 percent of emergent patients were seen within the triage target time compared with 100 percent of non-urgent patients," the authors write. Results did not differ for patients with or without insurance, or for those of different racial or ethnic groups.

Many causes likely exist for increased wait times, the authors note. Per capita ED use has increased during the same timeframe, with much of the increase among less acutely ill patients. Moreover, high hospital occupancy rates decrease the number of beds available for patients admitted through the ED.

"The multifactorial nature of prolonged ED wait time lends itself to numerous avenues for improvement," the authors conclude. These include increasing patients' access to alternate sites of care; interventions to improve ED processes; and redesign of the physical environment. "Comparative research into the most effective methods of reducing ED crowding, decreasing ED length of stay and limiting ED wait times is urgently needed to help EDs prioritize their quality improvement activities and maximize their impact."

"What are the consequences of ED crowding? Crowding in the ED has been associated with poorer process measures, including delays in treatment of pain, delays in antibiotic treatment for community-acquired pneumonia and decreases in the satisfaction of patients with their ED stay and hospitalization. There is also increasing evidence to suggest that ED crowding is associated with poorer clinical outcomes, such as increased in-hospital morbidity and mortality."