Scale Heterogeneity in Healthcare Discrete Choice Experiments: A Primer
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Discrete choice experiments (DCEs) are used to quantify the preferences of specified sample populations for different aspects of a good or service and are increasingly used to value interventions and services related to healthcare. Systematic reviews of healthcare DCEs have focussed on the trends over time of specific design issues and changes in the approach to analysis, with a more recent move towards consideration of a specific type of variation in preferences within the sample population, called taste heterogeneity, noting rises in the popularity of mixed logit and latent class models. Another type of variation, called scale heterogeneity, which relates to differences in the randomness of choice behaviour, may also account for some of the observed ‘differences’ in preference weights. The issue of scale heterogeneity becomes particularly important when comparing preferences across subgroups of the sample population as apparent differences in preferences could be due to taste and/or choice consistency. This primer aims to define and describe the relevance of scale heterogeneity in a healthcare context, and illustrate key points, with a simulated data set provided to readers in the Online appendix.
The authors wish to thank Dr Arne Hole from the University of Sheffield for reading and commenting on a draft of the manuscript.
All authors were involved in the drafting and editing of the manuscript, and Michael Burton was also involved in the simulation of choice data.
Compliance with Ethical Standards
No ethical approval was required for this study.
Conflict of interest
Caroline M. Vass and Katherine Payne were supported in the preparation and submission of this paper by Mind the Risk, from The Swedish Foundation for Humanities and Social Sciences. The views and opinions expressed are those of the authors and are not necessarily those of other Mind the Risk members or The Swedish Foundation for Humanities and Social Sciences. Stuart Wright and Michael Burton declare that they have no conflicts of interest.
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