Estimating parametric relationships between health description and health valuation with an application to the EuroQol EQ-5D

Generic health status measures classify patients into different health stat es. For example, the EQ-5D descriptive system developed by the EuroQol Grou p classifies patients into 243 health states. Empirical values for the heal th states are available for only a selection (mostly 12 to 45) of these hea lth states. Several parametric relationships between the descriptive system and the known values can be formulated to estimate the values for the unre corded health states. This paper describes several of these modeling exerci ses in a comprehensible way, using the EQ-5D as an illustration. It is show n that the estimation task does not depend on the meaning of the values, bu t does depend on the selection of the empirically valued health states and the assumptions about the relationship between these values and the descrip tive system. (C) 1999 Elsevier Science B.V. All rights reserved.