CDS alerts about dose, cost impact imaging test orders

Educating referring physicians about the costs of imaging exams, as well as radiation dose, can result in many of them changing their ordering decisions, according to a study published online in the journal Medical Care.

In the study, researchers led by Ron Gimbel, interim chairman of biomedical informatics at the Uniformed Services University of the Health Sciences, asked 112 family physicians to order a diagnostic imaging study for a symptomatic hypothetical patient. Of the 112 participants, 64 percent were residents and 77.5 percent were under the age of 40.

The hypothetical patient was a 22-year-old female who had a previously-detected renal mass. The participating physicians were given a choice of nine imaging options, after which they were presented with the American College of Radiology's appropriateness criteria for each exam and then given the chance to modify their imaging orders. Afterward, the participants were presented with dose information, followed by exam cost--or vice versa--and were again given the option to modify their choice at any stage.

CT was the exam of choice for about half the participants, followed by ultrasound at 35.7 percent and MRI at 8 percent. After being shown the appropriateness criteria, those exam percentages either increased or decreased slightly.

However, for the group of 65 physicians who were presented with dose information first, learning about CT exam dose resulted in the number of CT orders decreasing from 32 to 14. No further change was recorded when they were informed of the cost. Ultrasound orders increased from 25 to 36, and when the physicians learned that ultrasound cost substantially less than CT or MRI, that number then increased to 45 (69 percent of the group).

For the group of 47 physicians given cost information first, 60 percent initially ordered a CT exam. After learning about the radiation dose associated with the exam, however, that number dropped to 31.9 percent. About 36 percent of physicians selected ultrasound first, but the number jumped from 17 to 31 when learning of ultrasound's low cost. When told there was no radiation associated with the ultrasound, meanwhile, that number increased by one.

"This study supports an expanding literature which suggests that physicians have a real knowledge gap regarding both the estimated radiation exposure and cost of medical imaging," Gimbel told

Displaying the cost of a test via computerized provider order entry systems prompted a 9 percent reduction in the number of tests ordered, according to a study published last month in JAMA Internal Medicine.

To learn more:
- read the study in Medical Care
- see the article in