Hospitals in Western Australia have seen CT scans skyrocket among injured patients admitted to their emergency departments, with the rate increasing by 176% between 2004 and 2015.

Researchers at the Curtin School of Population Health say this concerns them due to the amount of radiation exposure these patients are potentially being subjected to, as well as the costs they are being charged and whether or not the scans are necessary.

Lead author Dr. Ninh Ha says the increase did not lead to more diagnoses of severe injuries, less time in hospital or an obvious reduction in mortality. “It is important to understand whether CTs are warranted and to weigh harm versus benefit, including the impact of over-testing. Our research found no evidence that the increased use of CT scanning led to better patient outcomes,” she said in a statement.
Because they provide quick diagnoses, CTs have been used increasingly in EDs worldwide for cross-sectional imaging. Exposure to radiation via CT raises a small, long-term risk for cancer. A chest CT, for example, can expose a patient to the same amount of radiation in 400 chest X-rays.

The study took into account changes in both the volumes and type of injuries that led to admission into the ED. Compared to the rate increase for CT scans, researchers saw the number of injury-related ED presentations only increased by 65% during the 11-year period. Further research will include observing patients throughout the full course of their treatment to more accurately measure radiation exposure, potentially across multiple CT scans. This will help identify any subgroups of the population that are at higher risk of exposure to excessive radiation.

While there are guidelines to help determine the appropriate use of CT, Ha says no high-level target for how often CT should be used depending on population, injury type or department level exists. She says that clinicians and health policy makers should reassess the frequent use of CT to balance its benefits and harms for optimum care delivery. “This study should serve as a call for healthcare policy makers to pay more attention to evaluating the current use of CT and to ensure healthcare resources are used appropriately by minimizing harms whilst striving for the highest-quality care possible.”

Despite these findings, a review by the Australian Radiation Protection and Nuclear Safety Agency in 2018 found that patients down under were receiving much lower doses from CTs than five to 10 years before. In addition, the agency recently developed free Occupational Radiation Exposure (ORE) training for all people working in medical facilities that use ionizing radiation, including for X-rays, CT and nuclear medical scans, it said on its website.

The COVID-19 pandemic initially led to a decrease in imaging exams in the U.S., with one study showing nearly 3.7 million fewer CT scans in 2020. A decline of 38,000 CT scans was seen on an average day during the worst parts of the crisis, with the largest drops in areas with higher-density populations and greater unemployment. This may have changed as healthcare facilities resume delayed exams and more patients feel comfortable coming in for visits. As a consequence of missing or having earlier visits cancelled, many are showing more advanced diseases that are harder to treat or incurable.

The study by Ha and her colleagues is part of a project led by Professor Rachael Moorin at the Curtin School of Population Health.

The findings were published in Academic Emergency Medicine.

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