title: Parameterising User Uptake in Economic Evaluations: The role of discrete choice experiments.
abstract: Model-based economic evaluations of new interventions have shown that user behaviour (uptake) is a critical driver of overall impact achieved. However, early economic evaluations, prior to introduction, often rely on assumed levels of uptake based on expert opinion or uptake of similar interventions. In addition to the likely uncertainty surrounding these uptake assumptions, they also do not allow for uptake to be a function of product, intervention, or user characteristics. This letter proposes using uptake projections from discrete choice experiments (DCE) to better parameterize uptake and substitution in cost-effectiveness models. A simple impact model is developed and illustrated using an example from the HIV prevention field in South Africa. Comparison between the conventional approach and the DCE-based approach shows that, in our example, DCE-based impact predictions varied by up to 50% from conventional estimates and provided far more nuanced projections. In the absence of observed uptake data and to model the effect of variations in intervention characteristics, DCE-based uptake predictions are likely to greatly improve models parameterizing uptake solely based on expert opinion. This is particularly important for global and national level decision making around introducing new and probably more expensive interventions, particularly where resources are most constrained.
authors.affiliation: Social and Mathematical Epidemiology (SaME), Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Fern
authors.initials: F
authors.lastname: Terris-Prestholt
authors.affiliation: Social and Mathematical Epidemiology (SaME), Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Quaife
authors.affiliation: Social and Mathematical Epidemiology (SaME), Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, UK.|School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Vickerman
mesh_terms: D002755:Choice Behavior; D003258:Consumer Behavior / Q000191:economics*; D003362:Cost-Benefit Analysis / Q000379:methods; D003657:Decision Making; D004470:Economics, Medical; D017048:Health Care Costs; D006302:Health Services Research; D006801:Humans; D018803:Models, Economic; D013019:South Africa
keywords: discrete choice experiments; economic evaluation; low-income and middle-income country; mathematical modelling; uptake; user preferences