title: Are people consistent when trading time for health?
abstract: The conventional, or standard, time trade-off (TTO) procedure, which is used to elicit the values that people place on health states that are in turn required to calculate quality adjusted life-years (QALYs), asks respondents to trade off fewer life years for better health. It is possible to reverse the procedure to ask respondents to trade off less health for more life years. Theoretically, these two procedures should generate the same TTO values for any given health state. This article reports that for health states defined by differing frequencies of migraine attack, the standard TTO gives health state values that are significantly higher than those given by the reverse TTO. The observed systematic procedural invariance, which substantiates some previous findings reported in the literature and is consistent with a loss aversion effect, challenges the validity of the TTO for generating reliable valuations of health states.
authors: Department of Social Policy, London School of Economics, Houghton Street, London WC2A 2AE, UK. Electronic address: a.j.oliver@lse.ac.uk.
authors: Adam
authors: A
authors: Oliver
authors: Department of Philosophy, University College London, Gower Street, London WC1E 6BT, UK. Electronic address: j.wolff@ucl.ac.uk.
authors: Jonathan
authors: J
authors: Wolff
mesh_terms: D003362:Cost-Benefit Analysis; D003657:Decision Making; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008881:Migraine Disorders; D019057:Quality-Adjusted Life Years; D012107:Research Design; D013997:Time Factors
keywords: Loss aversion; Procedural invariance; Time trade-off