Visual analog scales, standard gambles, and relative risk aversion.
BACKGROUND
It has been argued that visual analog scales (VASs) elicit an individual's measurable value function. The theoretical link between an individual's measurable value function v(.) and his or her von Neumann-Morgenstem utility function u(.) appears to provide a justification for transforming VAS scores into standard gamble (SG) utilities. However, VAS scores have been found to be subject to the effects of context, which casts doubt that the procedure is properly revealing v(.).


METHODS
The authors tested for the effects of context on VAS and SG scores. They also explored whether the range-frequency (R-F) model of Parducci offers a means of correcting VAS scores for the effects of context.


CONCLUSIONS
The R-F model may provide a means of correcting VAS scores for the effects of context, but no stable relationship exists between these corrected scores and SG utilities. Hence, there remain no grounds for transforming VAS scores into SG utilities.
Robinson
A
A
Department of Epidemiology and Public Health, University of Newcastle, Newcastle Upon Tyne, United Kingdom. angela.robinson@ncl.ac.uk
Loomes
G
G
Jones-Lee
M
M
D000063:Accidents, Traffic / Q000517:prevention & control / Q000706:statistics & numerical data; D006305:Health Status Indicators; D006801:Humans; D015233:Models, Statistical; D010147:Pain Measurement; D011379:Prognosis; D011788:Quality of Life; D012306:Risk; D012309:Risk-Taking; D014947:Wounds and Injuries / Q000453:epidemiology / Q000517:prevention & control