Emergency department (ED) physicians ordered more advanced medical imaging, especially for abdominal and chest pain, as the number of Americans seeking care in the ED rose from around 50 million to more than 61 million in an eight-year span ending in 2008, according to a report issued by the Centers for Disease Control and Prevention (CDC) in September.

Use of CT, MRI and ultrasound increased 122.6 percent for ED visits related to abdominal pain and 367.6 percent for visits related to chest pain from 1999 to 2008, according to the CDC.

The report included data for persons aged 18 and over whose visits were not related to an injury. According to the CDC, chest and abdominal pain account for the top reasons for ED visits among persons age 15 years and older. While symptoms vary in their acuity, advanced imaging is often ordered to diagnose or rule out serious illnesses, explained lead author Farida A. Bhuiya, MPH, of the CDC division of health care statistics, and colleagues.

Abdominal imaging on the rise
The authors found that the number of visits with abdominal pain as the primary cause increased 31.8 percent, from 5.3 million in 1999 to 2000 to seven million in 2007 to 2008. Although Bhuiya and colleagues reported no trend in visits categorized as immediate or emergent nor did they observe significant change in the percentage of visits that resulted in a serious diagnosis, they did find that physicians ordered more advanced imaging for abdominal pain. In 1999 to 2000, physicians ordered imaging for 19.9 percent of visits for abdominal pain. The percentage increased 122.6 percent to 44.3 percent of cases in 2007 to 2008, shared the researchers.

Trends in chest pain imaging
Although the percentage of ED visits with chest pain as the primary cause rose slightly from 5 million in 1999 to 2000 to 5.5 million in 2007 to 2008, the percentage triaged as immediate or urgent decreased by 12.4 percent and the percentage of these visits that resulted in a diagnosis of acute coronary syndrome decreased 44.9 percent from 23.6 percent in 1999 to 2000 to 13 percent in 2007 to 2008. Yet the use of advanced imaging swelled 367.6 percent during the decade, from 3.4 percent to 15.9 percent.

The impact of the trends may be mixed. “Advanced medical imaging may increase the amount of time that a patient spends in the ED, thereby slowing throughput and contributing to ED crowding and its adverse consequences,” wrote Bhuiya. “However, advanced imaging may help a physician to rule out certain conditions, thereby avoiding further unnecessary or risky diagnosis and therapy, and it may help confirm certain conditions, thereby leading to more effective and efficient therapy.”

The authors concluded that additional research is needed to determine the extent to which imaging assists diagnosis and treatment related to ED visits for abdominal or chest pain.