Informing physicians of the exact price of imaging tests at the point of order entry does little to sway utilization of MRI and other common exams, according to a study published online Jan. 2 in the Journal of the American College of Radiology.

Previous research has shown that referring physicians underestimate imaging costs, and the study was designed to assess whether cost transparency could significantly influence imaging utilization. Similar efforts aimed at presenting cost information have demonstrated a 27 percent reduction in the utilization of certain laboratory tests, explained authors Daniel J. Brotman, MD, of Johns Hopkins University School of Medicine in Baltimore, and colleagues.

“The impact of this strategy is especially relevant given that multiple current and proposed reforms at the state and federal levels are aimed at increasing healthcare price transparency,” wrote the authors.

Brotman and colleagues conducted a randomized controlled trial in which they integrated cost information alone into their center’s computerized physician order entry (CPOE) system, without the additional clinical decision support software (CDSS), to determine the impact of presenting costs on utilization. The 10 most frequently ordered imaging tests were identified from fiscal year 2007 data, with five being randomly assigned to the active cost display group and five to the control group. A six-month baseline period from Nov. 10, 2008, to May 9, 2009, in which no costs were displayed was compared with a seasonally matched period one year later in which costs were displayed for the active group.

Results showed a mean utilization change of +2.8 percent for the active group and -3.0 percent for the control group, but these differences were not statistically significant. There was also no significant correlation between test cost and utilization change for the active group compared with the control group, reported the authors.

“Provider cost transparency alone did not influence inpatient imaging utilization or its associated costs in any significant fashion,” wrote Brotman et al.

In speculating as to why cost transparency has such a large effect on lab tests but not imaging, the authors suggested it’s plausible that because many low-unit-cost lab tests are hastily ordered on a daily basis, the presentation of cost information may highlight the real financial consequences of such automatic ordering.

“Imaging tests, on the other hand, are widely known to be relatively expensive, even if the exact costs are somewhat underestimated,” wrote the authors. “Although physicians habitually order laboratory tests, they tend to actively decide to pursue imaging.”

CPOE systems are less costly than a full CDSS, though the results of the study indicate that cost information in a CPOE is no substitute for full-fledged decision support. Previous research has shown CDSS are associated with significant reductions in imaging utilization, according to the authors. “Thus, although CDSS may benefit by incorporating the strategy of increased cost transparency, our results suggest CDSS are superior to cost transparency as a stand-alone strategy.”