The purpose of this study was to estimate the cost effectiveness of ultrasonography and magnetic resonance imaging (MRI) as diagnostic modalities for suspected appendicitis in pregnancy. We examined the cost of ultrasound as the first-line modality with sequential MRI in the setting of a non-visualized appendix versus MRI alone.METHODS:
A cost-effectiveness model was created using TreeAge to compare the sequential ultrasound and MRI versus MRI alone in a theoretical cohort of 100,000 women. Outcomes examined included perforation of the appendix, cesarean delivery, maternal death, fetal death, cost, and quality-adjusted life years (QALY). Probabilities, utilities, and costs were derived from the literature, and a cost-effectiveness threshold was set at $100,000/QALY. One-way sensitivity analyses were used to evaluate the robustness of our results.RESULTS:
When comparing sequential ultrasound and MRI versus MRI alone for diagnosis of appendicitis in pregnancy, there were 3.5 fewer fetal deaths with sequential screening. There was no difference in rate of maternal death. There were higher QALYs associated with sequential screening, but MRI alone was cost-effective. With sensitivity analysis, sequential screen became cost-effective below $200 (cost assumption in our model was $604).CONCLUSION:
The sequential screening strategy led to fewer adverse neonatal outcomes. While this screening modality was not cost-effective, the higher QALYs make this screening algorithm worth considering in the clinical setting, especially due to improving clinician skills and the low cost of bedside ultrasound. Sequential screening is recommended as first-line imaging, and further investigation is warranted to better understand how these imaging modalities can improve clinical outcomes.