title: Towards a better QALY model.
abstract: This paper presents a test of the predictive validity of various classes of QALY models (i.e. linear, power and exponential models). We first estimated TTO utilities for 43 EQ-5D chronic health states and next these states were embedded in nonchronic health profiles. The chronic TTO utilities were then used to predict the responses to TTO questions with nonchronic health profiles. We find that the power QALY model clearly outperforms linear and exponential QALY models. Optimal power coefficient is 0.65. Our results suggest that TTO-based QALY calculations may be biased. This bias can be corrected using a power QALY model.
authors.affiliation: Department of Applied Economics, University of Murcia, Spain.
authors.forename: José-María
authors.initials: JM
authors.lastname: Abellán-Perpiñán
authors.forename: José-Luis
authors.initials: JL
authors.lastname: Pinto-Prades
authors.forename: Ildefonso
authors.initials: I
authors.lastname: Méndez-Martínez
authors.forename: Xabier
authors.initials: X
authors.lastname: Badía-Llach
mesh_terms: D006304:Health Status; D006306:Health Surveys; D006801:Humans; D015233:Models, Statistical; D019057:Quality-Adjusted Life Years; D015203:Reproducibility of Results; D013030:Spain