From the Journals

Initial ultrasound assessment of appendicitis curbs costs



Assessing appendicitis in children with initial ultrasound followed by computed tomography in the absence of appendix visualization and presence of secondary signs was the most cost-effective approach, according to data from a modeling study of 10 strategies.

Ultrasound is safer and less expensive than computed tomography and avoids radiation exposure; however, cost-effectiveness models of various approaches to imaging have not been well studied, wrote Rebecca Jennings, MD, of Seattle Children’s Hospital, Washington, and colleagues.

In a study published in Pediatrics, the researchers simulated a hypothetical patient population using a Markov cohort model and compared 10 different strategies including CT only, MRI only, and ultrasound followed by CT or MRI after ultrasounds that are negative or fail to visualize the appendix.

Overall, the most cost-effective strategy for moderate-risk patients was the use of ultrasound followed by CT or MRI if the ultrasound failed to visualize the appendix and secondary signs of inflammation were present in the right lower quadrant. The cost of this strategy was $4,815, with effectiveness of 0.99694 quality-adjusted life-years. “The most cost-effective strategy is highly dependent on a patient’s risk stratification,” the researchers noted. Based on their model, imaging was not cost effective for patients with a prevalence less than 16% or greater than 95%. However, those with appendicitis risk between 16% and 95% and no secondary signs of inflammation can forgo further imaging, even without visualization of the appendix for maximum cost-effectiveness, the researchers said.

The study was limited by several factors, including the inability to account for all potential costs related to imaging and outcomes, lack of accounting for the use of sedation when assessing costs, and inability to separate imaging costs from total hospital costs, the researchers noted. However, the results suggest that tailored imaging approaches based on patient risk are the most cost-effective strategies to assess appendicitis, they said.

“The diagnosis and exclusion of appendicitis continues to be one of the primary concerns of providers who care for children with abdominal pain,” wrote Rebecca M. Rentea, MD, and Charles L. Snyder, MD, of Children’s Mercy Hospital Kansas City, Mo., in an accompanying editorial (Pediatrics. 2020 Feb;145:e20193349).

“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,” they said. Despite the potential of missed appendicitis, the use of an algorithm based on an initial ultrasound and previous possibility of appendicitis described in the study was the most cost effective, they said. In addition, “the ability to visualize the appendix did not alter the most cost-effective approach in those with a moderate risk of appendicitis (most patients),” they concluded.

The study was supported by the University of Washington and Seattle Children’s Hospital Quality Improvement Scholars Program. The researchers had no financial conflicts to disclose.

Dr. Rentea and Dr. Snyder had no financial conflicts to disclose.

SOURCE: Jennings R et al. Pediatrics. 2020. doi: 10.1542/peds.2019-1352.

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