Tailored Imaging Most Cost-Effective for Suspected Appendicitis in Kids

By Reuters Staff

January 23, 2020

NEW YORK (Reuters Health) - For children with suspected appendicitis, tailored approaches to imaging based on risk of appendicitis are most cost-effective, say researchers from Seattle Children's Research Institute.

Based on a decision-analytic model they created, imaging is not worth it in patients with a risk of appendicitis lower than 16% and higher than 95%, Dr. Rebecca Jennings and her colleagues report Pediatrics.

For patients at moderate risk for appendicitis (between 16% and 67%), the most cost-effective strategy is initial ultrasound followed by a CT scan only if the appendix was not visualized and secondary signs of appendicitis (periappendiceal fluid collections, free fluid, hyperemia, fat stranding, bowel wall edema, or appendicolith) are present (cost of $4815.03; effectiveness of 0.997 quality-adjusted life-years).

In this moderate-risk group, it's okay to forgo additional imaging if the ultrasound does not visualize the appendix but shows no secondary signs of inflammation, the researchers say.

When the pretest probability tops 67%, it is cost-effective to follow-up all nonvisualized ultrasounds with a CT scan even without secondary signs of inflammation on ultrasound.

"The optimal imaging strategy is highly dependent on a patient's pretest probability of appendicitis; therefore, imaging strategies should be tailored on the basis of a provider's assessment of an individual patient's risk of appendicitis," write the researchers. "Providers can estimate a patient's appendicitis risk using ancillary tests or scores such as the Pediatric Appendicitis Risk Calculator or Pediatric Appendicitis Score."

In an editorial in Pediatrics, Dr. Rebecca Rentea and Dr. Charles Snyder of Children's Mercy Hospital Kansas City, Missouri, say, "The diagnosis and exclusion of appendicitis continues to be one of the primary concerns of providers who care for children with abdominal pain. The authors are to be congratulated on this nice addition to the evaluation of one of the most common pediatric surgical problems."

"The best diagnostic and imaging approach to appendicitis has been a topic of interest for some time, and improvements such as appendicitis scoring systems, decreased use of ionized radiation, and adoption of clinical algorithms have been incremental but steady. This article is another step forward," they note.

"The most cost-effective imaging approach in this article was based on the baseline previous probability of appendicitis, which may not be accurately known. As the authors note, an appendicitis algorithm (eg, pediatric appendicitis risk calculator, pediatric appendicitis score, Alvarado score) may help with risk stratification," they point out.

SOURCE: https://bit.ly/3ayuPFm and https://bit.ly/2TMlSST Pediatrics, online January 21, 2020.