http://repub.eur.nl/res/aut/14082/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/17855/ 2009-09-01T00:00:00Z The person tradeoff (PTO) is commonly used in health economic applications. However, to date it has no theoretical basis. The purpose of this paper is to provide this basis from a set of assumptions that together justify the most common applications of the PTO method. Our analysis identifies the central assumptions in PTO measurements. We test these assumptions in an experiment, but find only limited support for the validity of the PTO. http://repub.eur.nl/res/pub/10994/ 2004-03-01T00:00:00Z Previous empirical tests of quality-adjusted life-years (QALYs), the most widely used outcome measure in economic evaluations of health care, generally yielded negative results. These tests were, however, for the most part based on expected utility, which is now widely acknowledged to be descriptively inaccurate. The observed violations might, therefore, have been caused by violations of expected utility. We performed a new test of QALYs, which is valid under expected utility and under the two most influential non-expected utility theories, rank-dependent utility and prospect theory, and found considerable support for the QALY model. Our findings suggest that QALYs may be valid if nonexpected utility formulas are used to compute health state utilities. http://repub.eur.nl/res/pub/10995/ 2003-01-01T00:00:00Z Quality-adjusted life-years (QALYs) are the most common utility measure in medical decision analysis and economic evaluations of health care. This paper presents an axiomatization of QALYs under cumulative prospect theory (CPT), currently the most influential model for decision under uncertainty. Because the set of health states need not be endowed with a natural topology that is connected, we first show how existing CPT characterizations can be extended to a class of outcome sets for which no connected natural topology is given. We then characterize QALY models with linear, power, and exponential utility for duration. Finally, we define loss aversion for multiattribute utility theory and characterize the QALY models under general and constant loss aversion. The measurement of QALYs belongs to the general field of multiattribute utility theory. Hence, our results can be generalized to other multiattribute decision contexts and they thereby contribute to the development of multiattribute utility theory under cumulative prospect theory. http://repub.eur.nl/res/pub/11055/ 1998-01-01T00:00:00Z This paper studies the implications of the "zero-condition" for multiattribute utility theory. The zero-condition simplifies the measurement and derivation of the Quality Adjusted Life Year (QALY) measure commonly used in medical decision analysis. For general multiattribute utility theory, no simple condition has heretofore been found to characterize multiplicatively decomposable forms. When the zero-condition is satisfied, however, such a simple condition, "standard gamble invariance," becomes available. http://repub.eur.nl/res/pub/23099/ 1996-03-01T00:00:00Z Methods for determining the form of utilities are needed for the implementation of utility theory in specific decisions. An important step forward was achieved when utility theorists characterized useful parametric families of utilities and simplifying decompositions of multiattribute utilities. The standard development of these results is based on expected utility theory which is now known to be descriptively invalid. The empirical violations of expected utility impair the credibility of utility assessments. This paper shows, however, that parametric and multiattribute utility results are robust against the major violations of expected utility. They retain their validity under nonexpected utility theories that have been developed to account for actual choice behavior. To be precise, characterizations of parametric and multiattribute representations are extended to rank-dependent utility, state-dependent utility, Choquet-expected utility, and prospect theory.