While CT scans are invaluable for diagnosing life-threatening problems during an emergency examination, a new study suggests that too many physicians are ordering them when they may not be warranted.

Using data provided by the California Office of Statewide Health Planning and Development, researchers from the University of California San Francisco (UCSF) and Stanford looked at the treatments provided to more than 8 million patients at 348 California hospitals.

Each of those patients were seen — and discharged — from emergency departments after minor falls or low impact vehicle accidents. Of them, 3.51 percent underwent at least one CT scan in 2005 versus 7.17 percent in 2013, indicating that despite value-based care initiatives, utilization is increasing instead of decreasing.
In a statement, Dr. Renee Hsia, senior author of the study and UCSF professor of emergency medicine and health policy, said there may be several factors influencing CT usage.

"They range from defensive medicine practices, the superior diagnostic accuracy of CT scans compared with X-rays, to their increased availability and convenience in emergency departments, and the demand to expedite discharge of patients," said Hsia.

Level I and II trauma centers were also found significantly more likely to order CT scans than low-level centers that do not specialize in trauma care. In their report, published in the Journal of Surgical Research, the researchers suggest one factor could be that trauma centers see sicker patients and therefore require greater use of advanced imaging like CT.

The research also suggested that although utilization increased from 2005 to 2009, a decline took place from then until 2011. That reduction may possibly be attributed to awareness of overutilization and value-based treatment.

From 2011 to 2013 however, that trend was reversed and CT utilization almost reached the same peak it had in 2009.

Using CT scans when they are not necessary is not only expensive to the health system, it also exposes patients to unnecessary radiation. In a 2009 report, the FDA determined that a single CT scan may be associated with a fatal cancer in one of 2,000 patients.

Another example of CT overutilization has been uncovered as it pertains to treating dizziness. Research from the Kaiser Foundation Hospital in Honolulu found that 7.1 percent of those scans yield meaningful results. In the case of fainting patients, only 6.4 percent had useful CT scans.

There has also been increased scrutiny of using CT on pediatric patients. Research from the Mayo Clinic has outlined the overutilization of pediatric CT in the first decade of the 21st century, but also identified a marked decline in use. At Vanderbilt Children’s Hospital, for example, the number of CT studies from 2006 to 2015 dropped from 14,724 to 8,062 — about a 45 percent decline — despite increasing numbers of children seen in the their emergency department.

"We can't conclusively say which cases should not involve imaging, since every patient and every circumstance is different, but given that it is getting easier and easier to get CT scans, we need to be cautious in weighing their risks and benefits," said Hsia.

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