Physicians who manage emergency department (ED) visits ordered CT exams at a rate nearly three times that of nonphysicians, according to a study published in the November issue of American Journal of Roentgenology. However, the researchers who quantified CT ordering patterns could not identify a gatekeeper to CT.

As various stakeholders hone in on the appropriate use of CT, questions about gatekeeping to CT and ordering patterns among providers remain unanswered. At the same time, nonphysicians are independently managing more ED visits. In 2008, 10 percent of ED visits were managed solely by a physician extender, according to Christoph I. Lee, MD, from the department of radiology at University of Washington School of Medicine in Seattle, and colleagues.

Lee and colleagues sought to describe trends in CT ordering patterns by nonphysician providers in the ED and determine differences in ordering patterns between nonphysicians and physicians. They reviewed the 2001-2008 National Hospital Ambulatory Medical Care Survey data and found that the total number of ED visits managed without a physician grew from 5.9 million visits in 2001 to 11.1 million visits in 2008.

Nonphysicians increasingly turned to CT during the study period. In 2008, patient visits without a physician involved resulted in at least one CT exam 5.6 percent of the time. However, visits with a physician involved resulted in a CT exam 14.6 percent of the time. The researchers calculated that patients managed by nonphysicians had 0.38 times the odds of undergoing CT compared with those managed by physicians.  

The findings suggest nonphysician providers are less likely to order a CT scan than physicians, but Lee and colleagues could not identify the reason. “It may be,” they wrote, “that nonphysician health care providers follow protocol-driven practices regarding CT ordering more strictly whereas physicians may be subjectively influenced by a strong concern for malpractice liability (given that ultimate legal responsibility for patient care belongs to supervising physicians.)”

Other possible explanations include underuse of CT by nonphysicians or lower disease complexity among patients managed by nonphysicians.

Lee and colleagues suggested that future research focus on provider-specific practices leading to the difference in CT utilization. They added, “It remains unclear who the gatekeeper of this expensive powerful technology is and should be. Currently, there are few barriers for any provider type to order CT in the acute setting.”