The 15D instrument of health-related quality of life: properties and applications

The 15D is a generic, comprehensive, 15-dimensional, standardized, self-adm inistered measure of health-related quality of life (HRQoL) that can be use d both as a profile and single index score measure. This paper examines the acceptability, reliability, validity, discriminatory power and responsiven ess to change of its health state descriptive system and valuation system a nd presents some examples of applications, As a profile measure on roughly comparable dimensions the 15D performs equally well as the Nottingham Healt h Profile (NHP) and SF-20, in some respects even better, and clearly better than EQ-5D, The remaining nine to ten dimensions of the 15D provide a larg e reserve in terms of discriminatory power and responsiveness to change, Th e valuation system is based on an application of the multiattribute utility theory. The single index score (15D score) on a 0-1 scale, representing th e overall HRQoL, is calculated from the health state descriptive system by using a set of population-based preference or utility weights, The 15D scor es are shown to be highly reliable, sensitive and responsive to change, gen eralisable at least in Western-type societies, and particularly valid for d eriving quality-adjusted life years (QALYs) gained for resource allocation purposes. The instrument is recommended by the Washington Panel and is avai lable in several languages for clinical economic evaluation and population studies.