CDS reduces inappropriate imaging in the ED

By Kate Madden Yee, staff writer

March 29, 2019 -- Inappropriate orders for advanced imaging in the emergency department (ED) decrease when hospitals use clinical decision-support (CDS) tools, according to a study published in the April issue of the American Journal of Roentgenology.

The findings support the idea that CDS tools can help hospitals improve the effectiveness of ED imaging, which can be prone to overuse of advanced modalities such as CT and MRI, wrote a team led by Dr. Jashvant Poeran of Icahn School of Medicine in New York City.

Appropriate imaging is crucial in a patient-centered, belt-tightening healthcare environment, the researchers noted.

"Electronic health record-embedded clinical decision-support tools are increasingly used to direct appropriate use of imaging resources," they wrote. "Several major health institutions have reported on the effectiveness of CDS tools, both on a system-wide scale and stratified by clinical setting and indication."

Immediate feedback

The use of CDS software when ordering exams can reduce overuse or inappropriate use of imaging by providing immediate feedback to referring physicians, Poeran and colleagues wrote. They sought to evaluate the effectiveness of CDS on the use of advanced imaging in the ED, applying the American College of Radiology's ACR Select clinical decision support for CT and MRI orders in the emergency department.

ACR Select scores exam orders on a scale of 1 to 9, with higher scores representing more appropriate exams. The researchers based their study on data from CT and MR exams performed between April 2013 and June 2016 (AJR, April 2018, Vol. 212:4, pp. 859-866).

The team organized the data into three categories, based on feedback provided to referring physicians on the appropriateness of their orders. The threshold for delivering feedback was lowered in the second follow-up period, resulting in more feedback notices being delivered:

  • Before decision support (2013-2014): 5,602 exams. There was no scoring of exam appropriateness during this period.
  • After decision support -- period 1 (2014-2015): 7,176 exams. Ordering physicians with exam scores of 4 or less received active feedback.
  • After decision support -- period 2 (2015-2016): 14,771 exams. Ordering physicians with exam scores of 6 or less received active feedback.

The overall percentage of inappropriate orders (exams scored 1-3) decreased between pre-CDS and post-CDS period 2, from 18.9% to 10.2% -- a result that was statistically significant, the researchers found.

Effect of CDS on appropriateness of ED orders for advanced imaging
  Pre-CDS Post-CDS period 1 Post-CDS period 2 p-value
Overall percentage of inappropriate orders 18.9% 19.1% 10.2% < 0.0001

The group also assessed whether CDS affected house staff differently than attending physicians, theorizing that its effect would be more pronounced in less-experienced doctors. But, in fact, there was no statistically significant difference in appropriateness scoring between house staff and attending physicians in the pre-CDS or two post-CDS periods.

"Our hypothesis was that we would find differences between the two groups of ordering providers," Poeran told via email. "But we did not find such differences, even after various analyses. This was surprising, as house staff/nonhouse staff differences have been observed in other examples, such as antibiotic prescribing and lab test ordering. The main difference here may be that advanced imaging is more expensive than most antibiotics and lab tests, and this increases the threshold to order. Also, CTs and MRIs are ordered less frequently than lab tests."


The study demonstrates that, overall, CDS tools are effective in increasing appropriate imaging. The fact that CDS showed no statistically significant differences in physicians of different levels of experience could be due to a variety of factors, the researchers wrote.

"Our investigation reiterates the positive effect of CDS tools in increasing the rate of appropriate imaging use," they wrote. "Although our study revealed no significant difference in the effect of CDS on house staff physicians compared to nonhouse staff physicians, the results likely reflect the multifactorial influences of ordering behavior on our health system. CDS tools may thus serve as an equalizer in directing quality patient care from physicians across the training spectrum with varying familiarity with Appropriateness Criteria."

In any case, further research is needed, Poeran told

"Some ideas for future research could be to evaluate house staff by year of residency; to evaluate the effect of house staff specialty -- for example, the difference between ED compared to medicine compared to surgery residents; and to assess the effect of decision support by provider subgroup for lower-cost imaging such as radiographs," he said.

Copyright © 2019

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