Is there a case for using Visual Analogue Scale valuations in Cost-Utility Analysis?

This paper critically reviews theoretical and empirical propositions regarding visual analogue scale (VAS) valuations of health states and their use in Cost Utility Analysis. An oft-repeated conclusion in the economic evaluation literature is the inferiority, on theoretical grounds, of VAS valuations. Common criticisms are that VAS lacks a theoretical foundation; that VAS values are not ‘choice based’; that VAS values are not consistent with utility-under-uncertainty requirements; and that context and range effects observed in VAS valuation data mean that they cannot even be considered to represent measurable value functions.We address each of the above points, critically reviewing the economic and psychometric literature relating to theories of utility and theories of utility measurement, and the welfarist and non-welfarist literature relating to social choices and QALYs.We conclude that there are strong grounds, both theoretical and empirical, for challenging the apparently emerging consensus that VAS valuations should not be used in economic assessments. The theoretical appeal of alternatives such as the standard gamble is valid only at the level of individuals, rather than social decision-making. Further, the non-welfarist foundations of CUA do not require health state valuations to be grounded in any particular theory of utility, suggesting that the selection of the appropriate valuation method should be based on empirical performance. The VAS has important advantages over rival techniques such as standard gamble and time trade-off. However, we identify a number of areas in which further research is required to establish and consolidate the potential of VAS as a valuation method.