Introduction of contagious animal diseases into The Netherlands: elicitation of expert opinions

Abstract

This paper describes an experiment aimed at the derivation of information on Foot-and-Mouth Disease, Classical and African Swine Fever, Swine Vesicular Disease, Newcastle Disease and Avian Influenza to be used in an economic model to simulate introduction of a virus into the Netherlands. Several elicitation techniques, including three-point estimation, Conjoint analysis and ELI were used in the experiment. Three-point estimation (asking for minimum, most likely, and maximum values) was used to derive information concerning the length of the High Risk Period (HRP), during which the virus may spread freely. Conjoint analysis is widely used in marketing and consumer science and was used in this experiment to elicit the relative importance of risk factors which may introduce disease into the Netherlands (such as import of livestock, import of animal products, etc.). The ELI-technique (ELIcitation of uncertain knowledge) originates from the area of mathematical psychology and was used to derive information on the expected number of outbreaks of the diseases under consideration in European countries. The experiment was conducted with 43 (out of 50) invited people, all involved in or related to disease control in one way or another. The participants expected, for all diseases, the longest HRP in countries of eastern Europe. Import of livestock was evaluated as the most important risk factor for all diseases under consideration. Most outbreaks within the next five years were expected to occur in countries of eastern Europe, the smallest number in the Netherlands and the Scandinavian countries. Results especially showed that Conjoint analysis and ELI are useful tools to help quantify subjective knowledge. These subjective elicitation methods may not reveal the `Golden Standard' but as long as `objective' predictive information is not available, use of these tools may be valuable to enhance quality of input and output of economic simulation models to support policy-making in the prevention and control of contagious animal diseases.