In one study of 200 patients administered radiographic imaging tests without the use of decision rules at a level 1 trauma center, "169 underwent CT scanning, resulting in a total of 660 scans. If ACR appropriateness criteria had been applied (which they were not), 44% of these CT scans would not have been performed, but none of the patients with clinically significant injuries would have been excluded from CT imaging," Brenner wrote.
If the ACR's appropriateness criteria DSS system had been applied, Brenner added, "there would have been an estimated 38% decrease in imaging costs in addition to the 44% decrease in CT use and the associated decrease in radiation exposure."
Other larger studies "suggest that 20 to 40% of CT scans could be avoided if decision guidelines are followed, without compromising patient care," he wrote.
Of course there are many defensive legal reasons, and some dealing with patient demand, that influence decisions about what imaging test doctors order.
But there are too many important reasons why doctors should want to participate in this demonstration project. Payers and providers as well as patients need to make sure that these expensive and potentially harmful tests are ordered only when they do more good than harm.