An economic evaluation of sonographic examination of children with suspected appendicitis

Appendicitis is the most common surgical emergency presenting in the pediatric population. Approximately one third of these patients present with equivocal signs and symptoms frequently resulting in inpatient observation or additional diagnostic investigation. Although sonographic examination of patients with suspected appendicitis has been shown to be a highly accurate diagnostic modality, the cost effectiveness of this technology in the pediatric population has not been addressed. The economic value of this examination can be evaluated using a structured decision analysis.

The authors constructed a decision analysis model of treatment strategies for 2 groups of patients with a suspected diagnosis of acute appendicitis. Patients were categorized as either presenting with a "definitive acute abdomen" or "equivocal examination." Data drawn from published literature reports of the sensitivity and specificity of ultrasound, institution-specific cost data, and expert judgment were used to construct 2 decision trees. These data were used to determine the least costly diagnostic strategy for each group of patients, and sensitivity analysis performed to assess the robustness of the conclusions.

The use of ultrasonography in patients with "an acute abdomen" is not cost efficient and results in average additional cost of $234 per patient. In patients with equivocal diagnoses who are discharged from the emergency room after a negative ultrasound examination finding results in an average cost savings of $260 when compared with admission and observation. Patients who are discharged without examination incur an average additional cost of $373 as a result of the high cost of a missed diagnosis resulting in a perforated appendix.

The use of ultrasonography can be recommended for children with suspected appendicitis and equivocal examinations who are discharged from the emergency room after a negative examination result.