Quality of life dimensions are important considerations when patients evaluate pharmaceutical products with respect to personal benefits. Traditionally, standard gamble, time trade-off, and rating scale techniques are used to obtain preference (utility) estimates for various quality of life dimensions. This study examines three objectives to determine the feasibility of using conjoint analysis to elicit patient preferences for a particular health state. For the first objective, patients with multiple myeloma were asked to select quality of life conditions for 18 hypothetical patients with cancer and to indicate which conditions were the easiest and hardest to live with. Second, patients were asked to rate several cancer-related and general symptoms using visual analog scales. Third, comparisons were made between the two techniques to determine similarity and validity. Results revealed that conjoint analysis is useful for health-related quality of life research, and that conjoint analysis results compare favorably with values obtained from visual analog scales.
Von NeumannJMergensternO. Theory of Games and Economic Behavior.2nd ed.Princeton, NJ: University Press; 1947.
3.
KeeneyRLRaiffaH. Decisions with Multiple Objectives.New York, NY: Cambridge University Press; 1993:131–139.
4.
LuceRDTukeyJW. Simultaneous conjoint measurement: A new type of fundamental measurement. J Mathematical Psychol.1964;1:1–27.
5.
TorranceGWFeenyDHFurlongWJBarrRDZhangYWangQ. Multiattribute utility function for a comprehensive health status classification system. Med Care.1996;34(7):702–722.
6.
Addington-HallJMMacDonaldLDAndersonHR. Can the Spitzer quality of life index help to reduce prognostic uncertainty in terminal care?Br J Cancer.1990;62:695–699.
7.
SpitzerWODobsonAJHallJChestermanELeviJShephardRRenaldoBattista NCatchloveBR. Measuring the quality of life of cancer patients. J Chron Dis.1981;34:585–597.
8.
CoatesAThomsonDMcLeodGRMHerseyPGillPGOlverINKeffordRLowenthalRMBeadleGWalpoleE. Prognostic value of quality of life scores in a trial of chemotherapy with or without interferon in patients with metastatic malignant melanoma. European J Cancer.1993;29A(12):1731–1734.
9.
WilsonIBClearyPC. Linking clinical variables with health-related quality of life: A conceptual model of patient outcomes. JAMA. 1995;273(1): 59–65.
10.
The EuroQol Group.EuroQol—A new facility for the measurement of health-related quality of life. Health Policy.1990;16:199–208.
11.
Uyl-deGroot CARuttenFFHBonselGJ. Measurement and valuation of quality of life in economic appraisal of cancer treatment. Eur J Cancer.1994; 30A:111–117.
12.
NiezgodaHEPaterJL. A validation study of the domains of the core EORTC quality of life questionnaire. Quality Life Res.1993;2:319–325.
13.
BrazierJJonesNKindP. Testing the validity of the Euroqol and comparing it with the SF-36 Health Survey questionnaire. Qual Life Res.1993;2:169–180.
PriceDDBushFMLongSA comparison of pain measurement characteristics of mechanical visual analogue and simple numerical rating scales. Pain.1994;56:217–226.
16.
GuyattGHTownsendMBermanLBKellerJL. A comparison of likert and visual analogue scales for measuring change in funtion. J Chronic Dis.1987;Vol 40(12):1129–1133.
17.
DrummondMFStoddartGLTorranceGW. Methods for the Economic Evaluation of Health Care Programmes.Oxford: Oxford Medical Publications, Oxford University Press; 1992.
18.
ThurstoneLL. Attitudes can be measured. Am J Sociol.1928;33:529–554.
SzeinbachSLBarnesJHGarnerDD. Building brand equity in the pharmaceutical industry through value-added services: an application of maximum difference conjoint analysis using best-worst scaling. J Business Res.1997;40:226–236.
21.
HorowitzJLLouviereJJ. Testing predicted choices against observations in probabilistic discrete-choice models. Marketing Sci.1993;12(3):270–279.
22.
LynchJG. Uniqueness issues in the decompositional modeling of multiattribute overall evaluations: an information integration perspective. J Marketing Res.1985;22:1–19.
23.
LouviereJJFinnATimmermansH. Retailing research. In McGraw-Hill Handbook of Marketing Research.New York: McGraw-Hill Book Company; 1992.
24.
LouviereJJSwaitJAndersonD. Best-worst conjoint: theory, methods and comparisons with choice-based conjoint and reported marketplace choices. Working Paper, University of Florida, 1995.
25.
WareJESherbourneCD. The MOS 36-item Short-Form Health Survey (SF-36). I. Conceptual framework and item selection. Med Care.1992;30:473–483.
26.
McHorneyCAWareJEJr.RaczekAE. The MOS 36-item Short-Form Health Survey (SF-36):II. Psychometric and clinical tests of validity in measuring physical and mental health constructs. Med Care.1993;31:247–263.
27.
JackW. Pharmaceutical differentiation through quality of life measurement: a case study. J Pharm Mark Man.1991;6:65–85.
28.
MelzackR. The McGill pain questionniare; major properties and scoring methods. Pain.1975; 1227–1299.
CresswellSMEnglishPJRobertsJTMarshMM. Pain relief and quality-of-life assessment following intravenous and oral clodronate in hormone-escaped metastatic prostate cancer. Br J Urol.1995;76:360–365.
31.
KahnemanDTverskyA. Prospect theory: an analysis of decision under risk. Econometrica.1979;47(2): 263–291.
32.
KrupnickAJCropperM. The effect of information on health risk valuations. J Risk Uncertainty.1992;5:29–48.
33.
ViscusiWKipWMHuberJ. Pricing environmental health risks: A survey assessment of risk-risk and risk-dollar trade-offs for chronic bronchitis. J Environmental Econ Manage.1991;21:32–51.
