Oral ondansetron administration in emergency departments to children with gastroenteritis: an economic analysis

Abstract

Background: The use of antiemetics for children with vomiting is one of the most controversial decisions in the treatment of gastroenteritis in developed countries. Ondansetron, a selective serotonin receptor antagonist, has been found to be effective in improving the success of oral rehydration therapy. However, North American and European clinical practice guidelines continue to recommend against its use, stating that evidence of cost savings would be required to support ondansetron administration. Thus, an economic analysis of the emergency department administration of ondansetron was conducted. The primary objective was to conduct a cost analysis of the routine administration of ondansetron in both the United States and Canada.

Methods and findings: A cost analysis evaluated oral ondansetron administration to children presenting to emergency departments with vomiting and dehydration secondary to gastroenteritis from a societal and health care payer's perspective in both the US and Canada. A decision tree was developed that incorporated the frequency of vomiting, intravenous insertion, hospitalization, and emergency department revisits. Estimates of the monetary costs associated with ondansetron use, intravenous rehydration, and hospitalization were derived from administrative databases or emergency department use. The economic burden in children administered ondansetron plus oral rehydration therapy was compared to those not administered ondansetron employing deterministic and probabilistic simulations. We estimated the costs or savings to society and health care payers associated with the routine administration of ondansetron. Sensitivity analyses considered variations in costs, treatment effects, and exchange rates. In the US the administration of ondansetron to eligible children would prevent approximately 29,246 intravenous insertions and 7,220 hospitalizations annually. At the current average wholesale price, its routine administration to eligible children would annually save society US$65.6 million (US$49.1-US$81.1) and health care payers US$61.1 million (US$46.2-US$76.3). In Canada the administration of ondansetron to eligible children would prevent 4,065 intravenous insertions and 1,003 hospitalizations annually. Its routine administration would annually save society CDN$1.72 million (CDN$1.15-CDN$1.89) and the health care system CDN$1.18 million (CDN$0.88-CDN$1.41).

Conclusions: In countries where intravenous rehydration is often employed, the emergency department administration of oral ondansetron to children with dehydration and vomiting secondary to gastroenteritis results in significant monetary savings compared to a no-ondansetron policy. Please see later in the article for the Editors' Summary.

Figure 1. Tree structure used in the decision model.

The tree structure was too large to demonstrate using a single figure and has been divided up into two sections labeled (A) and (B). Entry into tree (A) requires that the child meet eligibility criteria (vomited on the day of presentation and evidence of dehydration). The two strategies evaluated are presented after the decision node, indicated by a square in (A). Each possible outcome (i.e., vomiting, intravenous rehydration) is presented on a tree branch after a chance node, shown as a circle on the tree. The complete tree is symmetrical beginning from the left of (A) and moving to the right, through (B) with the “yes” and “no” arms being identical as represented by the number 1. The costs and outcomes were entered at the payoff node, indicated by a triangle at the end of the models in both (A) and (B). An individual simulated patient can be followed through the tree by starting with the treatment choice in (A) and moving through the tree. The patient will have the potential to develop an outcome on the basis of the probabilities present at each chance node and are presented in Table 1. At the end of the tree, the total cost for that simulated patient is calculated on the basis of the treatment received and the outcomes experienced. Yes implies ondansetron is administered to all in addition to ORT; no implies standard of care (ORT) is administered but ondansetron is not administered. IV, intravenous.

Figure 2. Tornado diagram showing the influence of changing values of any variable on per patient costs.

Tornado diagram showing the influence of changing values of any variable on per patient costs when other variables remain at their base values. In the graph, variables are ranked on the basis of their influence (the most influential variable is on the top). Only variables that had more than 1% effect in the expected value were included. IV, intravenous.