Time to tweak the TTO: results from a comparison of alternative specifications of the TTO

Matthijs M Versteegh,Mark Oppe,Arthur E Attema,Nancy J Devlin,Elly A Stolk

doi:10.1007/s10198-013-0507-y

Matthijs M Versteegh, Mark Oppe + Show 3 more

Open Access

https://doi.org/10.1007/s10198-013-0507-y

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Abstract

This article examines the effect that different specifications of the time trade-off (TTO) valuation task may have on values for EQ-5D-5L health states. The new variants of the TTO, namely lead-time TTO and lag-time TTO, along with the classic approach to TTO were compared using two durations for the health states (15 and 20 years). The study tested whether these methods yield comparable health-state values. TTO tasks were administered online. It was found that lag-time TTO produced lower values than lead-time TTO and that the difference was larger in the longer time frame. Classic TTO values most resembled those of the lag-time TTO in a 20-year time frame in terms of mean absolute difference. The relative importance of different domains of health was systematically affected by the duration of the health state. In the tasks with a 10-year health-state duration, anxiety/depression had the largest negative impact on health-state values; in the tasks with a 5-year duration, the pain/discomfort domain had the largest negative impact.

Highlights

This article examines the effect that different specifications of the time trade-off (TTO) valuation task may have on values for EQ-5D-5L health states
It was found that lag-time TTO produced lower values than lead-time TTO and that the difference was larger in the longer time frame
Classic TTO values most resembled those of the lag-time TTO in a 20-year time frame in terms of mean absolute difference

Summary

Introduction

Attempts to improve the measurement of health-state values have led to several methodological innovations in valuation techniques such as the time trade-off (TTO), which are used to determine the desirability of a hypothetical state of health. Novel specifications of the classic approach to TTO have been developed to make the measurement of health states considered ‘worse than dead’ (WTD) more accurate [1]. To help fill that gap, the classic approach to TTO (here referred to as ‘classic TTO’) and two novel methods (lead-time TTO and lag-time TTO) have been compared in an online study. Classic TTO applies two different procedures for the valuation of health states that are considered better than dead and those considered WTD. TTO values for health states better than dead and WTD may not lie on the same utility scale [2]. While values for health states better than dead are restricted to points between 0 and 1, the values measured with the procedure for WTD can become very low [4, 5]. An arbitrary transformation of those values is subsequently needed to avoid distortion of the mean value

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