Appendicitis scoring systems drop CT use while also taking down diagnostic accuracy
Using appendicitis scoring systems to select suitable patients for CT exams can reduce imaging use but also causes a substantial loss of diagnostic accuracy, according to research published Tuesday.
Pre-operative imaging is standard for diagnosing acute appendicitis and, as a result, CT utilization has skyrocketed over the past few decades. Consequentially, physicians have sought efforts to more carefully select those who undergo exams and reduce radiation exposure in this setting, authors explained in Radiology.
They tested five different scoring systems’ effectiveness in triaging young adults with appendicitis, yielding “disappointing results.”
Although CT rates were reduced by 56%-71%, sensitivities and specificities both dropped compared to utilizing exams in all patients.
“Even when both target sensitivity and specificity were lowered to 95%, the clinical scoring systems yielded small CT reduction rates ranging from 0.1% (2 of 2888) to 11.2% (324 of 2888),” Hyunjoo Song, of Soongsil University in Seoul, South Korea, and colleagues explained May 18.
The findings are based on a retrospective study of 2,888 patients ages 15-44 gathered from a prior multicenter randomized controlled trial performed between December 2013 and August 2016. Overall, 1,088 participants were diagnosed with appendicitis across 20 teaching hospitals while the remaining 1,800 were not.
The World Society of Emergency surgery guidelines suggests using clinical scoring systems for selective CT utilization. But Song and colleagues said had they done so as recommended, a “considerable proportion” of patients would have been misdiagnosed and experienced complications.
Vincent M. Mellnick, MD, with Washington University School of Medicine’s Mallinckrodt Institute of Radiology, noted the results appear to support widespread use of CT rather than a selective approach, he wrote in an accompanying editorial.
At the same time, he pointed out scoring systems and diagnostic imaging are not mutually exclusive and others have shown more promising results than those published in this study.
“Perhaps the best approach is to use both clinical scoring and imaging in all patients, particularly in cases with equivocal imaging findings,” Mellnick explained Monday. “Although the large number of patients and pragmatic design of the [study] are strengths, concerns may still persist about the generalizability of these results given the limited age range of the study patients.”
Read more from the study authors here and the editorial here.
Matt joined Chicago’s TriMed team in 2018 covering all areas of health imaging after two years reporting on the hospital field. He holds a bachelor’s in English from UIC, and enjoys a good cup of coffee and an interesting documentary.