Despite increased ED visits, imaging rates stabilize

Growth in CT and MRI rates in emergency department (ED) visits has slowed over the past decade, according to a study published online Jan. 23 in the Journal of the American College of Radiology

While searching for areas to cut health care spending, experts frequently focus on diagnostic imaging due to concerns of uncontrolled overutiliziation, according to the authors Vignesh A. Arasu, MD, with the Department of Radiology and Biomedical Imaging at the University of California, San Francisco, and colleagues at Massachusetts General Hospital in Boston.

“The ED is frequently cited as one of the more expensive patient encounters, partly because radiology constitutes a greater proportion of the total costs of an average ED patient visit, among other concerns,” Arasu and colleagues wrote.

For this retrospective study, the researchers reviewed imaging trends in ED visits at Massachusetts General between 1996 and 2012. They reviewed aggregated billing data from 1.4 million diagnostic radiologic exams ordered for ED visits during the study period and the growth rates between 1996 and 2003 were compared against rates between 2004 and 2012.

The results showed that ED visit rates and imaging volumes grew from 1996 to 2012. Visits to the ED grew in that period by 3 percent annually.

Overall growth in total ED imaging exam rates, however, was not consistent. From 1996 to 2003, imaging per ED visit grew 4 percent per year, but decreased by 2 percent from 2004 to 2012.

Radiography was the most common imaging exam throughout the study, followed by CT, ultrasound and MRI.

“By modality, statistically significant decreased growth was observed in CT and MRI from 2004 to 2012,” the authors wrote.

The authors attribute this decrease to the slowing of new imagining indications, stronger practice guidelines and increased use of ultrasound. Additionally, the increased number of visits to the ED may be driving up imaging numbers rather than overutilization.

“High overall volume cannot necessarily be criticized as overutilization without comparing case complexity and measuring benefit through positivity rates of examinations and its effects on care,” Arasu and colleagues wrote. “Increased utilization of advanced imaging modalities such as CT or MRI increases certainty and speed of diagnosis and treatment and potentially avoids other tests or unnecessary invasive procedures.”

The team concluded that although national dialogue continues to focus on image growth, the study showed that long-term stability in ED imaging is a reality.