Getting an Abdominal CT in the ED Could Depend on Age

CT utilization for assessing abdominal pain in the emergency department is headed in two different directions, depending upon whether the patient is a child or an adult.

In a study published Nov. 20 in the American Journal of Roentgenology, researchers from the University of California at San Francisco showed evidence that while CT rates in pediatric patients with abdominal complaints are on the decline, more adults are having these scans done. This drop in pediatric use could likely be attributed to an ultrasound-first protocol for suspected appendicitis – a condition that accounts for 2.56 percent of emergency visions for abdominal pain.

“Although trends in CT use have previously been reported for children and adults, our study is the first, to our knowledge, to contrast the two cohorts in the [emergency department] setting in a national representative sample,” said first author Ralph C. Wang, M.D., professor of emergency medicine, noting that more than 3 million people present to the emergency department annually with an abdominal pain complaint.

Having a better idea about these trends is useful, Wang’s team said, because while CT offers excellent diagnostic accuracy for appendicitis, it does present patients with radiation exposure and leads an increase of incidental findings.

In fact, abdominal CT use in children grew from 1.2 percent in 1997 to 16.6 percent in 2010. But, thanks to the influence of the Image Wisely and Image Gently campaigns, that trend has reversed with utilization dropping slightly by 2016. The picture for adult CT use is starkly different, however. From 1997 to 2016, the increase was steady, rising from 3.9 percent to 37.8 percent.

Courtesy: American Journal of Roentgenology

Diagnostic Imaging Use Trends Among Pediatric (above) and Adult (below) Patients in U.S. Emergency Department Visits for Abdominal Pain

Courtesy: American Journal of Roentgenology

Wang’s team made their determinations by analyzing data on CT and ultrasound use pulled from the National Hospital Ambulatory Medical Care Survey, totaling approximately 1.1 million actual sample visits. Use was measured both over time spent in visits for abdominal pain, as well as visits that resulted in an appendicitis diagnosis.

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But, when the team looked specifically at CT use in regard to appendicitis, they found that overall utilization was up for both pediatric and adult emergency department visits – rising from 5.2 percent to 71 percent for children and growing from 7.2 percent to 83.3 percent for adults. And, among those visits that resulted in an appendicitis diagnosis, CT was involved in 70 percent of pediatric patients, as well as 80 percent of adults.

The team did, however, pick up on a disparity in their analysis. African American and Hispanic adult and pediatric patients alike were less likely to receive CT scans, they determined.

In addition, the team uncovered a difference when it comes to location of service. Children with abdominal pain and a diagnosis of appendicitis evaluated in the pediatric emergency department were at decreased odds of receiving CT than were those evaluated in general emergency department, specifically a 0.6 pain odds ratio and a 0.2 appendicitis odds ratio.

“Use of CT to evaluate abdominal pain in adults, already two to three times as frequent as for pediatric patients, continued to increase throughout the study period, peaking in 2015-2016,” the team said. “The increase over time in CT use for adult was not associated with an increase in the proportion of diagnoses of appendicitis during visits for abdominal pain, suggesting that the increase in CT use may not benefit patients but instead results in more patients without appendicitis receiving CT.”

Related Content: Diagnostic Imaging in ED Varies for Adults with Suspected Appendicitis​

During the same study time frame, ultrasound use among pediatric patients with abdominal pain quadrupled, the team said, from 4.3 percent in 1997 and 1998 to 15.9 percent in 2015 and 2016 with more children undergoing an ultrasound than a CT by study’s end. The rise in ultrasound utilization among adults during the same time period was more modest, increasing from 10.5 percent to 16.6 percent.

Ultimately, the team said, implementing diagnostic scans can help providers identify the patients who need the most emergent help, but it is encouraging to see that efforts still continue to limit the amount of radiation exposure for the youngest patients.

“The increased use of imaging overall may allow providers to exclude serious diagnoses and avoid prolonged observation and inpatient hospitalization. We did observe a decrease in the proportion of patients with abdominal pain who were admitted to the hospital,” the team concluded. “We believe that the decrease in use of CT to evaluate abdominal pain in children is related to successful nationwide research and implementation efforts to decreased radiation exposure to children.”

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