Risk-based imaging most cost-effective approach in children with potential appendicitis

Tailoring imaging-based protocols to children’s risk of appendicitis is the most cost-effective approach for diagnosis, according to a Jan. 21 analysis published in Pediatrics.

After analyzing a number of techniques, researchers determined that imaging should not be performed when a patient has a less than 16% risk or above 95% risk for appendicitis. Rebecca Jennings, with Seattle Children’s Research Institute and colleagues, believe utilizing more efficient strategies could spare patients from unnecessary radiation while also improving value.

“Accurate diagnosis of appendicitis can be challenging, with consequences for both false-positive and false-negative diagnoses,” Jennings and co-authors wrote. “It is important to minimize potential negative consequences of imaging, including radiation, incidental findings and costs.”

Given that imaging, along with physician’s assessment, is critical to diagnosing appendicitis, those figures can be rather high. According to some estimates, the condition costs $278 million annually, placing it as the fifth most costly pediatric condition at general hospitals.

And while prior studies have assessed the cost-effectiveness of varying imaging protocols for diagnosing appendicitis—the most common cause for pediatric emergency surgery—none have evaluated MRI and ultrasound that did not visualize the appendix or did not separate patients according to risk, the authors noted.

Jennings et al. created a decision-analytic model of 10 imaging strategies in a hypothetical group of patients.

In children at moderate risk for appendicitis (16% to 67%), they found the most cost-friendly approach is initial ultrasound with subsequent CT only when the appendix is obscured and secondary indications of the condition are present. This cost $4,815,03 and yielded 0.997 quality-adjusted life-years.

When pretest probability of appendicitis is higher than 67%, the authors wrote, clinicians should follow-up all non-visualized ultrasounds with a CT scan, even without secondary signs of inflammation on ultrasound.

“Our results suggest all hospitals should adopt risk stratification followed by eventual ultrasound in patients with intermediate probability of appendicitis,” the researchers wrote.

Still, they maintained, the “optimal imaging strategy” depends on the patient’s pretest probability of appendicitis. Imaging protocols should ultimately be tailored based on a clinician’s assessment of a child’s specific risk of the condition.