Michael Jonathan Wan BSc, Presenter: Nothing to Disclose

Murray Krahn, Abstract Co-Author: Nothing to Disclose

Wendy Ungar, Abstract Co-Author: Nothing to Disclose

Lillian Sung, Abstract Co-Author: Nothing to Disclose

Andrea Schwarz Doria MD, Abstract Co-Author: Nothing to Disclose

The purpose of this study was to compare the cost-effectiveness of ultrasonography (US) versus computed tomography (CT) in the diagnosis of pediatric appendicitis using a Markov decision analytic model.

A Markov-based decision model was constructed using costs, utilities and probabilities taken from the literature. The risk of radiation-induced malignancy following a single abdominal CT scan was estimated using the BEIR VII report by the National Academy of Sciences (NAS), which was based primarily on data from atomic bomb survivors. The base case was a five-year-old child presenting with suspected appendicitis. Patients were divided into two hypothetical cohorts, one undergoing US and the other undergoing CT. The model simulated the treatment and long-term survival of the patients, keeping track of health care costs and average quality-adjusted lifespan.

Based on the effective radiation dose from a full abdominal CT scan in a five-year-old child, it was estimated that there would be 81.1 radiation-induced malignancies per 100,000 in males and 97.2 radiation-induced malignancies per 100,000 in females. In the baseline model, US was marginally more effective (longer quality-adjusted lifespan) than CT. With US, females lived an additional 0.0056 quality-adjusted life years (QALYs) and males lived an additional 0.0029 QALYs compared to CT. Average health care costs per patient were $10,865 with US and $11,785 with CT. US remained less costly than CT in all sensitivity analyses, even when the cost of treating radiation-induced cancer was ignored.

In a Markov-based decision model of pediatric appendicitis, the choice between US and CT had minimal impact on average quality-adjusted lifespan. However, with US, average health care costs were estimated to be almost $1,000 less per patient than with CT.

Both US and CT are effective at facilitating the diagnosis of appendicitis in young children, but US is more cost-effective and therefore recommended as the initial imaging strategy when available.

Wan, M, Krahn, M, Ungar, W, Sung, L, Doria, A, Cost-Effectiveness of Ultrasonography versus Computed Tomography in the Diagnosis of Acute Appendicitis in Children: A Markov Decision Analytic Model.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5004054.html