Visual analog scales (VASs) have long been used as a method of measuring preferences for health outcomes. They are easy and inexpensive to implement, can be administered quickly, and lend themselves to self-completion. Over time, however, disturbing questions have emerged concerning the validity of the VAS approach. This article reviews briefly the history, theory, practice, problems, and advantages of VASs; presents some suggestions to improve the validity of VASs; and recommends a limited but useful role for VASs in the process of measuring preferences for health states.
Drummond MF, O’Brien BJ, Stoddart GL, Torrance GW. Methods for the Economic Evaluation of Health Care Programmes. 2nd ed.Oxford: Oxford University Press, 1997.
2.
Patrick D, Bush J, Chen M.Methods for measuring levels of well-being for a health status index. Health Serv Res. 1973;8:228-245.
3.
Torrance GW. Social preferences for health states: an empirical evaluation of three measurement techniques. Socio-Economic Planning Sci. 1976;10:129-136.
4.
Torrance GW, Boyle MH, Horwood SP. Application of multiattribute utility theory to measure social preferences for health states. Oper Res. 1982;30:1043-1069.
5.
Bleichrodt H, Johannesson M.An experimental test of a theoretical foundation for rating scale valuations. Med Decis Making. 1997;17:208-216.
6.
Schwartz A.Rating scales in context. Med Decis Making. 1998;18:236.
7.
Robinson A, Loomes G, Jones-Lee M.Visual analog scales, standard gambles and relative risk aversion. Med Decis Making. 2001;21:17-27.
8.
Krantz DH, Luce RD, Suppes P, Tversky A.Foundations of Measurement. New York: Academic Press, 1971.
Gafni A, Torrance G.Risk attitude and time preference in health. Mgmt Sci. 1984;30:440-451.
11.
von Winterfeldt D, Edwards W.Decision Analysis and Behavioural Research. Cambridge: Cambridge University Press, 1986.
12.
Poulton E.Models for biases in judging sensory magnitude. Psychol Bull. 1979;86:777-803.
13.
Feeny DH, Furlong WJ, Boyle MH, Torrance GW. Multiattribute health status classification systems: health utilities index. Pharmacoeconomics. 1995;7:490-502.
14.
Brooks R.EuroQol: the current state of play. Health Policy. 1996;37:53-72.
15.
Parducci A, Wedell DH. The category effect with rating scales: number of categories, number of stimuli, and method of presentation. J Exp Psychol. 1986;12:496-512.
16.
Streiner DL, Norman GR. Health Measurement Scales: A Practical Guide to Their Development and Use. Oxford: Oxford University Press, 1989.
17.
Sinclair AJ, Burton JFJ. Development of a schedule for compensation of non-economic loss: quality of life values vs. clinical impairment rating. In: Chaykowski RP, Thomason T, eds. Research in Canadian Workers’ Compensation. Kingston, Ontario: Industrial Relations Centre, Queen’s University Press, 1995:123-140.
18.
Furlong W, Feeny D, Torrance GW, et al.Multiplicative Multi-Attribute Utility Function for the Health Utilities Index Mark 3 (HUI3) System: A Technical Report. Hamilton, Ontario: Centre for Health Economics and Policy Analysis, McMaster University. Working Paper 98-11.
19.
Read J, Quinn R, Berwick D, Fineberg H, Weinstein M.Preferences for health outcomes—comparisons of assessment methods. Med Decis Making. 1984;4:315-329.
20.
Elstein A, Holzman G, Ravitch M, et al.Comparison of physicians’ decisions regarding estrogen replacement therapy for menopausal women and decisions derived from a decision analytic model. Am J Med. 1986;80:246-258.
21.
Boyd N, Sutherland H, Heasman K, et al.Whose utilities for decision analysis?Med Decis Making. 1990;10:58-67.
22.
Bass EB, Steinberg E, Pitt H, et al.Comparison of the rating scale and the standard gamble in measuring patient preferences for outcomes of gallstone disease. Med Decis Making. 1994;14:307-314.
23.
Krabbe PFM, Essink-Bot ML, Bonsel GJ. The comparability and reliability of five health-state valuation methods. Soc Sci Med. 1997;45:1641-1652.
24.
Patrick D, Starks H, Cain K, Uhlmann R, Pearlman R.Measuring preferences for health states worse than death. Med Decis Making. 1994;14:9-18.
25.
Wolfson AD, Sinclair AJ, Bombardier C, McGeer A.Preference measurements for functional status in stroke patients: inter-rater and inter-technique comparisons. In: Kane R, Kane R, eds. Values and Long Term Care. Lexington, MA: D. C. Heath, 1982:191-214.
26.
Torrance GW, Feeny DH, Furlong WJ, Barr RD, Zhang Y, Wang Q.Multiattribute utility function for a comprehensive health status classification system: Health Utilities Index mark 2. Med Care. 1996;34:702-722.
27.
Feeny D, Townsend M, Furlong W, et al.Assessing Health-Related Quality-of-Life in Prenatal Diagnosis, Comparing Chorionic Villi Sampling and Anmiocentesis: A Technical Report. Hamilton, Ontario: Centre for Health Economics and Policy Analysis, McMaster University, 2000. Working Paper 00-04.
28.
Le Galès C, Buron C, Costet N, Rosman S, Slama G. Développement d’un index d’etats de santé pondéré par les utilités en population française: le Health Utilities Index. Economie et Prévision, in press.
