What, who and when? Incorporating a discrete choice experiment into an economic evaluation.

Michela Tinelli,Mandy Ryan,Christine Bond

doi:10.1186/s13561-016-0108-4

Abstract

BackgroundEconomic evaluation focuses on Quality-Adjusted-Life-Years (QALYs) as the main valuation method. However, it is well known that factors beyond health related quality of life are important to patients and the public. Whilst discrete-choice-experiments (DCE) have been extensively used to value such factors, their incorporation within an economic evaluation framework is limited. This study is the first to incorporate patient preferences for factors beyond QALYs into an economic evaluation and compare results with the standard cost-per-QALY approach, using randomised-controlled-trial (RCT) participants.MethodsCostings, clinical-effectiveness (appropriateness-of-treatment), QALYs and patient satisfaction data were collected at baseline and 12-month follow-up for a new pharmacy-service within a randomised-controlled-trial. Trial participants who replied to the follow-up survey and had not subsequently withdrawn from the study were mailed a DCE questionnaire at 24-months. WTP for the standard and new service was derived from the DCE. Results from QALYs and the DCE were compared.ResultsAt 12 months, costs, clinical-effectiveness and QALYs did not differ between the intervention and control; however there was a significant increase in satisfaction in the intervention. The DCE valued this increased satisfaction in the intervention (positive net-benefit). The longer the time patients experienced the new service the greater the reported net-benefit.ConclusionWhen incorporating a DCE into an economic evaluation a number of questions are raised: what factors should be valued, whose values (trial-groups vs. all–trial-population) and when should they be elicited (still-receiving-the-intervention or afterwards). Consideration should also be given to status quo bias.Electronic supplementary materialThe online version of this article (doi:10.1186/s13561-016-0108-4) contains supplementary material, which is available to authorized users.

Highlights

Economic evaluation focuses on Quality-Adjusted-Life-Years (QALYs) as the main valuation method
Across trial groups: here it is assumed that the relevant Quality adjusted life year (QALY) and Willingness to pay (WTP) estimates come from the individuals that were part of the intervention group;
Within intervention group - here the relevant QALY and WTP estimate are compared between intervention subgroups either still receiving or not receiving the Medman service at the time of the Discrete Choice Experiments (DCEs) survey

Summary

Introduction

Economic evaluation focuses on Quality-Adjusted-Life-Years (QALYs) as the main valuation method. Whilst discrete-choice-experiments (DCE) have been extensively used to value such factors, their incorporation within an economic evaluation framework is limited. This study is the first to incorporate patient preferences for factors beyond QALYs into an economic evaluation and compare results with the standard cost-per-QALY approach, using randomised-controlled-trial (RCT) participants. Economic evaluation is an integral component of health care decision making. Discrete Choice Experiments (DCEs) were introduced into health economics in the early 1990s to value aspects of health care beyond health outcomes [1, 2]. Since their use has increased to address a broad range of policy questions. Two other studies ([4, 5]) included a DCE within a trial, but there was no comparable QALY data

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Discussion

Conclusion