Tell patients about CT risks

IMPROVED education for undergraduates, and shared decision-making with patients are the keys to curbing the overuse of imaging, says a leading Australian radiologist.

Professor Stacy Goergen, director of research at Southern Health’s Department of Diagnostic Imaging in Melbourne, said there was also a need to reinforce GP education and provide the right tools to facilitate communication with patients about balancing the risks and benefits of computed tomography (CT) scans.

Professor Goergen said information provided in a research letter published in JAMA Internal Medicine translated well to the Australian situation. (1)

The letter reported on a study to assess how often doctors discussed potential harms with patients before they had a CT scan.

The authors asked 286 patients undergoing outpatient CT at the Denver Veterans Affairs Medical Center in the US to complete a questionnaire to assess their knowledge of potential harms of CT and if they had been warned of risks.

The results showed 24% of respondents did not know of any risks associated with CT scans and another 24% considered the risks to be low.

A majority of respondents (62%) also believed that the final decision to undergo CT was mainly the physician’s, the authors wrote.

“A minority (35%) said they discussed the potential risks of the test with their health care provider. Only 17% reported all of the following prior to undergoing the CT scan: having a shared final decision, discussing the potential benefits, and discussing the potential risks with their health care provider.

“We believe it is problematic when the potential harms of CT are not adequately conveyed. Ignoring downsides can lead to imbalanced decision making in favour of overuse.

“Correcting the lack of knowledge and the lack of communication about the potential harms of imaging tests — thereby enhancing shared decision making — should be part of any attempt to curb imaging overuse. It is time to begin empirically testing risk communication methods and translate these methods into routine clinical practice”, the authors concluded.

Professor Goergen said studies in Australia had produced similar results. Tools were starting to be developed to improve communication between patients, referring GPs and radiologists, she said.

“The referrer has much more information about the benefits of undergoing the test”, Professor Goergen told MJA InSight. “The radiologist has much more information about the risks.”

She said when considering a CT scan, doctors needed to consider what information the imaging would provide that was not already known, “and that falls fairly and squarely with the referrer”.

“When the referrers have the conversation with the patient about the risks versus the benefits of the imaging test, then the patient ends up much more informed”, she said.

Professor Goergen cited InsideRadiology, a website developed by the Royal Australian and New Zealand College of Radiologists, as an example of the kind of readily available tool for both GPs and the general public. (2)

She also questioned whether undergraduate medical courses put enough emphasis on providing information about risks versus benefits in imaging. “But the information also needs to be reinforced with GPs later on.”

Professor Richard Mendelson, a consultant radiologist at the Royal Perth Hospital’s department of diagnostic and interventional radiology, has led the development of a tool called Diagnostic Imaging Pathways to provide an evidence-based radiology education and decision-support tool for clinicians. (3)

– Cate Swannell

1. JAMA Intern Med 2013; Online 4 March
2. InsideRadiology
3. WA Department of Health: Diagnostic Imaging Pathways

Posted 11 March 2013