Perspective

US EDs use low-value imaging more often than Canadian EDs

Photo of Eyal Cohen
Eyal Cohen

Recent findings demonstrated that pediatric EDs in the United States use more imaging for conditions that do not routinely require them for diagnosis, including constipation and abdominal pain, compared with pediatric EDs in Ontario, Canada.

“The problem with low-value diagnostic imaging is that it is costly and can impact the quality of care delivery,” study researcher Eyal Cohen, MD, MSc, a staff physician at The Hospital for Sick Children, told Infectious Diseases in Children. “Many diagnostic tests involve exposure to ionizing radiation, and many children need sedation to perform some tests, such as MRI. Diagnostic imaging interpretation is also not perfect and can lead clinicians down pathways to unnecessary treatment.”

Cohen and colleagues compared rates of overall and low-value use of diagnostic imaging in pediatric EDs in Canada and in the U.S. between 2006 and 2016. They used administrative health databases from four Ontario-based pediatric EDs and 26 pediatric EDs in the U.S.

The researchers included visits for conditions for which imaging is not routinely recommended, including asthma, bronchiolitis, abdominal pain, constipation, concussion, febrile convulsion, seizure and headache.

During the study period, 1,782,752 visits were reported in Ontario, and 21,807,332 visits were reported in the U.S.

Overall, American EDs used imaging more often than Canadian EDs, such as head CT (3.5% vs. 1.3%; P < .001), abdomen CT (1% vs. 0.3%; P < .001), chest X-rays (15.6% vs. 11.7%; P < .001) and abdominal X-rays (16.5% vs. 4.3%; P < .001).

When the researchers examined the reasons for imaging use, they found that U.S. EDs used low-value diagnostic imaging more often than Canadian EDs for several indications, including abdominal X-rays for constipation (absolute difference = 23.7%; 95% CI, 23.2%-24.3%) and abdominal pain (absolute difference = 20.6%; 95% CI, 20.3%-21%), and head CT scans for concussions (absolute difference = 22.9%; 95% CI, 22.3%-23.4%).

Cohen and colleagues wrote that although overall use of abdominal CT scans for constipation and abdominal pain were low, EDs in the U.S. used this type of imaging 10 times more often than Canadian EDs 1.2% vs. 0.1% and 7% vs. 0.8%, respectively.

According to the researchers, a lower rate of imaging use in Canada did not mean that adverse outcomes increased following discharge. They suggested that differences between U.S.- and Canadian-based EDs in terms of imaging use may be due to financial restrictions.

“Canadian physicians practice within a broader system of strict global budgets for hospitals and regional health authorities,” they said.

Differences in physician training or national guidelines, a “heightened perception of medicolegal risk,” patient and parent expectations, differing patient populations and rates of uninsurance and underinsurance may also explain the variances in low-value imaging use, they added.

“There have been a number of campaigns to try and reduce unnecessary imaging like Choosing Wisely, Image Wisely and Image Gently,” Cohen said. “Probably the best known is the Choosing Wisely campaign, which has focused on a variety of overuse in medicine, including diagnostic imaging. Choosing Wisely is partnering with professional associations in the U.S., Canada and many other countries to advance a dialogue among clinicians and their patients to reduce the use of unnecessary tests.”– by Katherine Bortz

Disclosures: Cohen reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.

Photo of Eyal Cohen
Eyal Cohen

Recent findings demonstrated that pediatric EDs in the United States use more imaging for conditions that do not routinely require them for diagnosis, including constipation and abdominal pain, compared with pediatric EDs in Ontario, Canada.

“The problem with low-value diagnostic imaging is that it is costly and can impact the quality of care delivery,” study researcher Eyal Cohen, MD, MSc, a staff physician at The Hospital for Sick Children, told Infectious Diseases in Children. “Many diagnostic tests involve exposure to ionizing radiation, and many children need sedation to perform some tests, such as MRI. Diagnostic imaging interpretation is also not perfect and can lead clinicians down pathways to unnecessary treatment.”

Cohen and colleagues compared rates of overall and low-value use of diagnostic imaging in pediatric EDs in Canada and in the U.S. between 2006 and 2016. They used administrative health databases from four Ontario-based pediatric EDs and 26 pediatric EDs in the U.S.

The researchers included visits for conditions for which imaging is not routinely recommended, including asthma, bronchiolitis, abdominal pain, constipation, concussion, febrile convulsion, seizure and headache.

During the study period, 1,782,752 visits were reported in Ontario, and 21,807,332 visits were reported in the U.S.

Overall, American EDs used imaging more often than Canadian EDs, such as head CT (3.5% vs. 1.3%; P < .001), abdomen CT (1% vs. 0.3%; P < .001), chest X-rays (15.6% vs. 11.7%; P < .001) and abdominal X-rays (16.5% vs. 4.3%; P < .001).

When the researchers examined the reasons for imaging use, they found that U.S. EDs used low-value diagnostic imaging more often than Canadian EDs for several indications, including abdominal X-rays for constipation (absolute difference = 23.7%; 95% CI, 23.2%-24.3%) and abdominal pain (absolute difference = 20.6%; 95% CI, 20.3%-21%), and head CT scans for concussions (absolute difference = 22.9%; 95% CI, 22.3%-23.4%).

Cohen and colleagues wrote that although overall use of abdominal CT scans for constipation and abdominal pain were low, EDs in the U.S. used this type of imaging 10 times more often than Canadian EDs 1.2% vs. 0.1% and 7% vs. 0.8%, respectively.

According to the researchers, a lower rate of imaging use in Canada did not mean that adverse outcomes increased following discharge. They suggested that differences between U.S.- and Canadian-based EDs in terms of imaging use may be due to financial restrictions.

“Canadian physicians practice within a broader system of strict global budgets for hospitals and regional health authorities,” they said.

Differences in physician training or national guidelines, a “heightened perception of medicolegal risk,” patient and parent expectations, differing patient populations and rates of uninsurance and underinsurance may also explain the variances in low-value imaging use, they added.

“There have been a number of campaigns to try and reduce unnecessary imaging like Choosing Wisely, Image Wisely and Image Gently,” Cohen said. “Probably the best known is the Choosing Wisely campaign, which has focused on a variety of overuse in medicine, including diagnostic imaging. Choosing Wisely is partnering with professional associations in the U.S., Canada and many other countries to advance a dialogue among clinicians and their patients to reduce the use of unnecessary tests.”– by Katherine Bortz

Disclosures: Cohen reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.

    Perspective
    Brett Burstein

    Brett Burstein

    The findings of this study are important. In an era of health care reform that must increasingly prioritize value of care, Choosing Wisely and similar national campaigns have probably done little to move the bar toward meaningful reductions of diagnostic imaging for many indications. 

    It is in this context that the authors presented a topical comparison of diagnostic imaging utilization in Canadian and U.S. pediatric EDs. They reported a higher proportion of overall and low-value diagnostic imaging among U.S. pediatric EDs compared with those in Ontario, particularly for imaging modalities with associated radiation exposure, such as X-rays and CT scans.  Of note, lower reliance on diagnostic imaging in Ontario was not associated with higher rates of adverse outcomes.

    Interestingly, the use of diagnostic imaging was higher in Ontario than in the U.S. for “high-value” control indications, refuting the notion that imaging is infrequently undertaken in Canada overall. It appears rather that in Canada, the right children are getting the right imaging.

    It is worth mention that in both the U.S. and Canada, most children (close to 90%) are not treated in specialized pediatric EDs, but rather nonpediatric community or general EDs. In general, pediatric hospitals tend to be more judicious with testing and radiation exposure for children. Thus, it is possible, even likely, that the findings reported here underestimate the true difference in unnecessary testing between U.S. and Canadian hospitals more broadly. 

    Excess imaging is associated with exposure to ionizing radiation, increased systemwide costs, and often unnecessary treatments and antibiotic use.

    The paper itself addresses many of the medicolegal drivers of excess imaging, which include but are not limited to fear of litigation, parental expectations, physician remuneration and insurance structures. Reduction of excess imaging is complex and likely requires a multimodal strategy targeting physicians, policymakers and the public.

    • Brett Burstein, MD, PhD, MPH, FRCPC, FAAP
    • Clinician-scientist
      Pediatric emergency physician
      Division of pediatric emergency medicine
      McGill University Health Centre