Campbell D & Erdem S (2019) Including opt-out options in discrete choice experiments: issues to consider. Patient, 12 (1), pp. 1-14. https://doi.org/10.1007/s40271-018-0324-6
Background: Providing an opt-out alternative in discrete choice experiments can often be considered to be important for presenting real-life choice situations in different contexts, including health. However, insufficient attention has been given to how best to address choice behaviours relating to this opt-out alternative when modelling discrete choice experiments, particularly in health studies.
Objective: The objective of this paper is to demonstrate how to account for different opt-out effects in choice models.We aim to contribute to a better understanding of how to model opt-out choices and show the consequences of addressing the effects in an incorrect fashion.We present our code written in the R statistics program so that others can explore these issues in their own data.
Methods: In this practical guideline, we generate synthetic data on medication choice and use Monte Carlo simulation. We consider three different definitions for the opt-out alternative and four candidate models for each definition. We apply a frequentist-based multimodel inference approach and use performance indicators to assess the relative suitability of each candidate model in a range of settings.
Results: We show that misspecifying the opt-out effect has repercussions for marginal willingness to pay estimation and the forecasting of market shares. Our findings also suggest a number of key recommendations for DCE practitioners interested in exploring these issues.
Conclusions: There is no unique best way to analyse data collected from discrete choice experiments. Researchers should consider several models so that the relative support for different hypotheses of opt-out effects can be explored.
Patient: Volume 12, Issue 1
|Publication date online||31/08/2018|
|Date accepted by journal||25/06/2018|