Our group recently published a clinical pathway (Le Bonheur Clinical Pathway [LeB-P]) that used the Samuel Pediatric Appendicitis Score with selective use of ultrasonography (USG) for diagnosis of children at risk for appendicitis. The objective of this study was to model the cost-effectiveness of implementing the LeB-P compared with usual care.

We constructed a decision analytic model comparing hospital costs for the following diagnostic strategies for suspected appendicitis: emergency department clinician judgment alone, USG on all patients, CT on all patients, overnight observation with surgical evaluation without studies, and the LeB-P. Prevalence of disease, outcomes probabilities, and hospital and professional costs for each option were derived from published literature, national cost data, and our previous study results. Cost-effectiveness was calculated using these 3 sets of parameters.

In the base case model, USG was the preferred strategy over LeB-P and overnight observation with surgical evaluation without studies. Emergency department clinician judgment alone and CT were dominated by the other pathways, based on either lower diagnostic accuracy or increased costs. Compared with LeB-P, USG costs $337 less per patient evaluated, but increased the diagnostic error rate by 2%. Using LeB-P rather than USG would cost an institution an additional $17,206 to eliminate one misdiagnosis, which is known as the incremental cost-effectiveness ratio.

Although performing USG on all children with suspected appendicitis was determined to be the most cost-effective strategy, using the Pediatric Appendicitis Score with selective use of USG (LeB-P) improved diagnostic accuracy at a moderate increase in cost and decreased CT use.