A study published in the Journal of the American College of Radiology found the use of advanced imaging in emergency departments (EDs) grew considerably over the past two decades, largely due to an aging population, crowded EDs and expanded indications for computed tomography (CT).

A group of researchers split between New York University and Emory University used the Household Component Emergency Room Visit File to collect patient-reported data on ED visits in a nationally representative survey of U.S. households.

“In comparison with traditional health services research using payer claims-based administrative data sets, unique insights into trends in imaging utilization can be obtained from patient-generated national survey data,” wrote lead author Andrew Rosenkrantz, MD, associate professor of radiology at NYU School of Medicine, and colleagues. “Patients are uniquely positioned to know the underlying reasons that prompted them to seek emergency care and are potentially free of classification biases and errors that may impact claims data." 

The authors found drastic increases in advanced imaging utilization in EDs: the number of ED visits where CT was preformed increased 16% every year from 1995 to 2007. Part of this is because EDs have become increasingly crowded, placing time pressures on care providers resulting in inadequate pre-imaging screening. Another contributing factor is the patient desire for imaging because it gives the impression of diagnostic certainty, according to the authors.

While evidence-based guidelines and clinical decision support systems serve as a counterweight to some of those factors, certain conditions saw increased advanced imaging without a corresponding decrease in ultrasound or radiography: additive imaging.

Stratifying ED visits by patient condition—something only possible with patient-reported data—allowed the authors to detect nuances that would be lost if utilization was only pared down to the modality level.

“Interestingly, for all combinations of modalities involving CT (e.g., CT with radiography, CT with ultrasound or CT with both radiography and ultrasound), the rate of duplicative imaging at a single visit for urinary calculus showed an initial increase followed by a subsequent decrease,” wrote Rosenkrantz et al. “This likely reflects an earlier tendency for ED physicians to obtain a CT after an initial radiograph or ultrasound, though later embracing CT as the first-line imaging modality for this condition once gaining increasing comfort with its diagnostic performance.”

Identifying specific clinical scenarios like this is the first step towards addressing runaway ED imaging, according to the authors.

“Recognizing the specific clinical contexts where imaging utilization has become most pronounced can help optimize the development of targeted solutions for avoiding potentially unneeded examinations and thereby curb further ED imaging growth,” wrote Rosenkrantz et al.

Co-authors on the study include Associate Professor of Radiology at NYU School of Medicine James S. Babb, PhD, Professor of Radiology at Emory University School of Medicine Richard Duszak Jr., MD, and Assistant Professor of Radiology Tarek N. Hanna, MD, also of Emory University.