Trauma CT use rose dramatically between 1996 and 2006, while utilization rates between adolescents and adults varied only subtlety, according a study published in the October edition of the Journal of the American College of Radiology (JACR).
"Several studies have addressed the higher susceptibility of children to carcinogenic consequences of radiation relative to adults. Because of this concern, several recommendations have been developed to minimize the inappropriate use of CT. ... However, the potential influences of these recommendations on utilization rates are not well investigated," Bahman Roudsari, MD, PhD, of the University of Washington, Seattle, and co-authors wrote.
The researchers sought to investigate trends in CT use at a level I trauma center between 1996 and 2006. The study paid particular attention to the rate of CT utilization in adolescents (aged 13 to 18 years) compared to CT use in adults, while also controlling for potential demographic confounders. The authors hypothesized that CT use would differ significantly between age groups.
The trauma center admitted a total of 47,004 patients in the 11-year study period, 10 percent of whom were between the ages of 13 and 18 (no one under 13 years was admitted to the facility). The authors found that CT use increased substantially, but that "all age groups experienced similar increases in crude utilization rate."
When controlling for motor vehicle injuries, intensive care unit admission and higher injury severity scores, all of which were associated with significantly greater probabilities of undergoing CT, the authors observed that adolescents were slightly more likely to undergo head CTs, but significantly less likely to be administered thoracic CTs than adults.
Adolescents were significantly more likely to undergo head CT scans in 2006 compared with 1996; however, this relationship did not exhibit a linear pattern over the 11-year study. Repetitive head CT use increased from 2 percent in 1996 to 19 percent in 2006 for the entire sample, the researchers observed.
The authors also found that "thoracic CT and other CT studies (including CT of the spine and extremities) demonstrated the most drastic increases in utilization." The incident risk ratio for thoracic CT in adolescents increased from 1.15 in 1997 to 10.53 in 2006.
The authors noted several limitations to the study. The fact that the study included patients from only one trauma center "could restrict the generalizability of our results," according to Roudsari and colleagues. The authors also acknowledged the importance of future studies differentiating spine, extremity and other CT studies and of evaluating the appropriateness of use for the CT scans, especially given the danger of adolescents' overexposure to radiation.
While the authors did not discover the dramatic differences in CT utilization between age groups that they had hypothesized, they argued that their comprehensive use of demographic and injury controls and an 11-year study period bolstered their main findings about CT increases over the 11-year period.