Download PDF
Physikalische Medizin, Rehabilitationsmedizin, Kurortmedizin 2005; 15(2): 76-82
DOI: 10.1055/s-2004-834714
Wissenschaft und Forschung
© Georg Thieme Verlag KG Stuttgart · New York

Development and Evaluation of an Interview Instrument for the Monetary Valuation of Expected and Perceived Health Effects Using Rehabilitation Interventions as a Model

Entwicklung und Evaluation eines Interviewinstruments zur monetären Bewertung von erwarteten und erfahrenen Gesundheitseffekten unter Verwendung von Rehabilitationsinterventionen als ModellM.  Brach1 , D.  Gerstner1 , A.  Hillert2 , A.  Schuster1 , N.  Sosnowsky2 , G.  Stucki1
  • 1Klinik und Poliklinik für Physikalische Medizin und Rehabilitation, Klinikum der Ludwig-Maximilians-Universität München (Direktor: Prof. Dr. med. G. Stucki)
  • 2Medizinisch-Psychosomatische Klinik Roseneck, Prien am Chiemsee
Further Information

Publication History

Eingegangen: 20. Januar 2005

Angenommen: 14. Februar 2005

Publication Date:
08 April 2005 (online)

Also available at
    Permissions and Reprints

Zusammenfassung

Fragestellung: Ziel dieser Pilotstudie war, die Entwicklung, Testung und Anpassung eines Interviewinstruments um die Zahlungsbereitschaft (Willingness-to-pay, WTP) für erwartete und erfahrene Gesundheitseffekte zu erheben. Modellhaft wurden Patienten mit Schmerzen oder Depression im Rahmen einer vollstationären oder teilstationären Rehabilitationsmaßnahme untersucht. Material und Methode: Das Instrument für das strukturierte Interview wurde mit Fokus auf Kriterien entwickelt, die einem validen Szenario entsprechen müssen. Es wurden folgende Fragen untersucht: 1. die allgemeine Verständlichkeit des WTP-Interviews, 2. die Machbarkeit, Geldbeträge für erwartete und erfahrene Gesundheitseffekte zu erheben, 3. Geldbeträge für den Umfang der Zahlungskarte für Contingent-Valuation(CV)-Studien in der Zielpopulation zu ermitteln und 4. die Validität der CV-Methode hinsichtlich bekannter Assoziationen der WTP mit dem Einkommen zu untersuchen. Ergebnisse: An der Studie nahmen 30 Patienten teil. Das entwickelte Instrument ist präzise und verfahrensrelevant. Die Studienteilnehmer empfanden es in der Anwendung im teilstationären und vollstationären Bereich verständlich, plausibel und bedeutungsvoll. Die Machbarkeit, Geldbeträge für erwartete und erfahrene Gesundheitseffekte mit dem WTP-Interview zu erheben war gut, mit hohen Responseraten von 93,3 % ex-ante und 95,2 % ex-post. Die ermittelten Geldbeträge lagen zwischen 20 und 2500 €. Die Zahlungskarte, zur Verwendung in CV Studien in der Zielpopulation, sollte deshalb einen Umfang von 0 - 1000 € und mehr umfassen. Die Validität der CV konnte hinsichtlich der positiven Assoziation der WTPmax ex-post mit dem verfügbaren Einkommen (R2 0,672; p < 0,002), dem Versicherungsstatus (R2 0,476; p < 0,034) und der Berufsausbildung (R2 0,507; p < 0,032) bestätigt werden. Schlussfolgerung: Der entwickelte Fragebogen wird im Rahmen des deutschen Gesundheitssystems für die untersuchte Population als geeignet betrachtet und ist valide bezüglich bekannter Assoziationen mit dem Einkommen, dem Versicherungsstatus und der Berufsausbildung. Die Spannbreite der Geldbeträge dient als Basis für eine Zahlungskarte, die in zukünftigen Studien in der Zielpopulation verwendet werden kann. Basierend auf dieser Studie, ist die WTP eine viel versprechende Methode um kleine bis mittlere Gesundheitseffekte einzuschätzen und zu bewerten.

Abstract

Purpose: The objective of this pilot study was to develop, test and modify an interview instrument to assess WTP for expected and perceived small to moderate health effects. To examine this objective, a comprehensive inpatient rehabilitation or day-clinic program for patients with pain or depression was used as a model. Material and method: The instrument for the structured interview was developed focusing on criteria considered as necessary and sufficient for a valid CV scenario. We then 1) examined the general comprehensibility of the WTP interview, 2) examined the feasibility of assessing the monetary value of expected and perceived health effects, 3) identified the range of monetary values for a payment scale to be used in contingent valuation (CV) studies in the target population and 4) explored the validity of the CV by examining known associations of the WTP with income. Results: 30 patients took part in the pilot study. The developed instrument for the structured interview is theoretically accurate and seems policy relevant. It was found to be comprehensible, plausible and meaningful by respondents as intended when applying it in the day-clinic and inpatient setting. The feasibility of the WTP interview to assess the monetary value of expected and perceived health effects was good with a high response rate of 93.3 % ex-ante and 95.2 % ex-post. The found monetary values ranged from € 20 to € 2.500. The range for a payment scale to be used in CV studies in the target population therefore needs to cover the range from € 0 to € 1.000 and more. The validity of the CV could be confirmed by the expected positive association of the ex-post WTPmax with disposable income (R2 0.672; p < 0.002), insurance status (R2 0.476; p < 0.034), and job qualification (R2 0.507; p < 0.032). Conclusion: The developed questionnaire was found to be suitable for the examined population in the context of the German health care system and is valid with respect to known and expected associations with income, insurance status and job qualification. The range of monetary values is the basis for a payment scale to be used in future studies in the target population. Based on this pilot study, WTP is a promising method for assessing the value of small to moderate health effects.

Schlüsselwörter

Willingness-to-pay - Contingent-Valuation - gesundheitsökonomische Evaluation - Gesundheitseffekte - Rehabilitation

Key words

Willingness-to-pay - contingent valuation - economic evaluation - health effects - rehabilitation

Literatur

  • 1 Murray C JL, Lopez D L. Global mortality, disability, and the contribution of risk factors: global burden of disease study.  Lancet. 1997;  349 1436-1442
    CrossrefPubMedGoogle Scholar
  • 2 Lawrence R C. et al . Estimates of the prevalence of selected arthritic and musculoskeletal disease in the United States.  J Rheumatol. 1989;  16 427-441
    PubMedGoogle Scholar
  • 3 Williams A. The economic role of „health indicators”. In: Teeling Smith G (ed) Measuring the Social Benefits of Medicine. London; Office of Health Economics 1983
    Google Scholar
  • 4 Drummond M F. et al .Methods for the Economic Evaluation of Health Care Programmes: Second Edition. New York, Oxford; Oxford University Press 1997
    Google Scholar
  • 5 Gold M R. et al (eds) .Cost-Effectiveness in Health and Medicine. New York, Oxford; Oxford University Press 1996
    Google Scholar
  • 6 Ryan M. et al . Eliciting public preferences for healthcare: a systematic review of techniques.  Health Technology Assessment (Winchester, England). 2001;  5 (5) 1-186
    PubMedGoogle Scholar
  • 7 Johannesson M, Jönsson B. Economic evaluation in health care: is there a role for cost-benefit analysis?.  Health Policy. 1991;  17 (1) 1-23
    CrossrefPubMedGoogle Scholar
  • 8 Donaldson C, Birch S, Gafni A. The distribution problem in economic evaluation: income and the valuation of costs and consequences of health care programmes.  Health Economics. 2002;  11 (1) 55-70
    CrossrefPubMedGoogle Scholar
  • 9 Bala M V, Zarkin G A. Are QALYs an appropriate measure for valuing morbidity in acute diseases?.  Healt Econ. 2000;  9 177-180
    PubMedGoogle Scholar
  • 10 Dieppe P. Therapeutic targets in osteoarthritis.  J Rheumatol. 1995;  22, Suppl 43 126-129
    PubMedGoogle Scholar
  • 11 Bellamy N. Outcome measurement in osteoarthritis clinical trials.  J Rheumatol. 1995;  22, Suppl 43 49-51
    PubMedGoogle Scholar
  • 12 Angst F, Aeschlimann A, Stucki G. Smallest Detectable and Minimal Clinically Important Differences of Rehabilitation Intervention With Their Implications for Required Sample Sizes Using WOMAC and SF-36 Quality of Life Measurement Instruments in Patients With Osteoarthritis of the Lower Extremities.  Arthritis Care & Research. 2001;  45 384-391
    PubMedGoogle Scholar
  • 13 Angst F. et al . Minimal Clinically Important Rehabilitation Effects in Patients with Osteoarthritis of the Lower Extremities.  J Rheumatol. 2002;  29 131-138
    Google Scholar
  • 14 Weigl M. et al . Inpatient rehabilitation for hip or knee osteoarthritis: 2 year follow-up study.  Ann Rheum Dis. 2004;  63 360-368
    CrossrefPubMedGoogle Scholar
  • 15 Diener A, O'Brien B, Gafni A. Health care contingent valuation studies: a review and classification of the literature.  Health Economics. 1998;  7 (4) 313-326
    CrossrefPubMedGoogle Scholar
  • 16 Klose T. The contingent valuation method in health care.  Health Policy. 1999;  47 (2) 97-123
    CrossrefPubMedGoogle Scholar
  • 17 Blumenschein K, Johannesson M. Use of contingent valuation to place a monetary value on pharmacy services: an overview and review of the literature.  Clinical Therapeutics. 1999;  21 (8) 1402-1417, discussion 1401
    CrossrefPubMedGoogle Scholar
  • 18 Bayoumi A M. The Measurement of Contingent Valuation for Health Economics.  Pharmacoeconomics. 2004;  22 (11) 691-700
    CrossrefPubMedGoogle Scholar
  • 19 Johannesson M. The contingent-valuation method.  Medical Decision Making. 1993;  13 (4) 311-312
    PubMedGoogle Scholar
  • 20 Johannesson M, Jönsson B. Economic evaluation of osteoporosis prevention.  Health Policy. 1993;  24 (2) 103-124
    CrossrefPubMedGoogle Scholar
  • 21 O'Brien B, Gafni A. When do the „dollars” make sense? Toward a conceptual framework for contingent valuation studies in health care.  Medical Decision Making. 1996;  16 (3) 288-299
    PubMedGoogle Scholar
  • 22 O'Conor R M, Johannesson M, Johansson P O. Stated preferences, real behaviour and anchoring: some empirical evidence.  Environmental & Resource Economics. 1999;  13 (2) 235-248
    PubMedGoogle Scholar
  • 23 Hanley N, Ryan M, Wright R. Estimating the monetary value of health care: lessons from environmental economics.  Health Economics. 2003;  12 3-16
    CrossrefPubMedGoogle Scholar
  • 24 Thompson M S, Read J L, Liang M. Feasibility of willingness-to-pay measurement in chronic arthritis.  Medical Decision Making. 1984;  4 (2) 195-215
    PubMedGoogle Scholar
  • 25 Smith R D. Construction of the contingent valuation market in health care: a critical assessment.  Health Economics. 2003;  12 609-628
    CrossrefPubMedGoogle Scholar
  • 26 Mitchell R, Carson R. Using Surveys to Value Public Goods: the Contingent Valuation Method. Resources for the Future. Washington, DC; Johns Hopkins University Press 1989
    Google Scholar
  • 27 Carson R T. Constructed markets. In: Braden JK, Kolstad CD (eds) Measuring the demand for environmental quality. Amsterdam; Elsevier/North Holland 1991
    Google Scholar
  • 28 Johannesson M, Johansson P O, Jönsson B. Economic evaluation of drug therapy: a review of the contingent valuation method.  Pharmacoeconomics. 1992;  1 (5) 325-337
    PubMedGoogle Scholar
  • 29 Arrow K. Uncertainty and the welfare economics of medical care.  Am Econ Rev. 1963;  53 941-973
    PubMedGoogle Scholar
  • 30 Olsen J A. et al . Willingness to pay for public health care: a comparison of two approaches.  Health Policy. 2004;  70 217-228
    CrossrefPubMedGoogle Scholar
  • 31 Dubourg W R, Jones-Lee M W, Loomes G. Imprecise preferences and survey design in contingent valuation.  Economica. 1997;  64 681-702
    CrossrefPubMedGoogle Scholar
  • 32 Norusis M. SPSS 12.0 Statistical Procedures Companion. Chicago; 2004
    Google Scholar
  • 33 Altman D G, Gardner M J. Statistics with confidence. In: Altman DG et al. (eds) Statistics with confidence. Bristol; BMJ Books 2000
    Google Scholar
  • 34 Thompson M S. Willingness to pay and accept risks to cure chronic disease.  American Journal of Public Health. 1986;  76 (4) 392-396
    PubMedGoogle Scholar
  • 35 Johannesson M, Jönsson B, Borgquist L. Willingness to pay for antihypertensive therapy-results of a Swedish pilot study.  Journal of Health Economics. 1991;  10 (4) 461-473
    CrossrefPubMedGoogle Scholar
  • 36 O'Brien B J. et al . Assessing the economic value of a new antidepressant. A willingness-to-pay approach.  Pharmacoeconomics. 1995;  8 (1) 34-45
    PubMedGoogle Scholar
  • 37 Lindholm C, Diderichsen F. Contingent valuation as a method for measuring the effects of rehabilitation.  International Journal of Rehabilitation Research. 1998;  21 87-92
    PubMedGoogle Scholar
  • 38 Arrow K. et al . Natural resource damage assessments: purposed rules.  Fed Regist. 1994;  59 1062-1191
    PubMedGoogle Scholar
  • 39 O'Brien B, Viramontes J L. Willingness to pay: a valid and reliable measure of health state preference?.  Medical Decision Making. 1994;  14 (3) 289-297
    PubMedGoogle Scholar
  • 40 Kartman B, Andersson F, Johannesson M. Willingness to pay for reductions in angina pectoris attacks.  Medical Decision Making. 1996;  16 (3) 248-253
    PubMedGoogle Scholar
  • 41 Blumenschein K, Johannesson M. Relationship between quality of life instruments, health state utilities, and willingness to pay in patients with asthma.  Annals of Allergy, Asthma & Immunology. 1998;  80 (2) 189-194
    PubMedGoogle Scholar
  • 42 Cross M J, March L M, Lapsley H M. Determinants of willingness to pay for hip and knee joint replacement surgery for osteoarthritis.  Rheumatology. 2000;  39 1242-1248
    CrossrefPubMedGoogle Scholar
  • 43 Unützer J. et al . Willingness to Pay for Depression Treatment in Primary Care.  Psychiatric Services. 2003;  54 (3) 340-345
    CrossrefPubMedGoogle Scholar
  • 44 Yeung R YT, Smith R D, McGhee S M. Willingness to pay ans size of health benefit: an integrated model to test for „sensitivity to scale”.  Health Economics. 2003;  12 791-796
    CrossrefPubMedGoogle Scholar
  • 45 Lachaine J, Laurier C, Contandriopoulos A-P. Defining Monetary Values for Quality of Life Improvements.  Pharmacoeconomics. 2003;  21 (12) 865-874
    PubMedGoogle Scholar
  • 46 Johannesson M, Liljas B, O'Conor R M. Hypothetical vs real WTP: some experimental results.  Applied Economics Letters. 1997;  4 (3) 149-151
    CrossrefPubMedGoogle Scholar
  • 47 Ajzen I, Brown T C, Carvajal F. Explaining the Discrepancy Between Intentions and Actions: The Case of Hypothetical Bias in Contingent Valuation.  PSPB. 2004;  30 (9) 1108-1121
    PubMedGoogle Scholar
  • 48 Neill H R. et al . Hypothetical surveys and real economic commitments.  Land Economics. 1994;  70 145-154
    PubMedGoogle Scholar
  • 49 Cummings R G, Harrison G W, Rutström E E. Home-grown values and hypothetical surveys: is the dichotomous choice approach incentive-compatible?.  American Economic Review. 1995;  85 260-266
    PubMedGoogle Scholar
  • 50 Champ P A. et al . Using donation mechanisms to value nonuse benefits from public goods.  Journal of Environmental Economics & Management. 1997;  33 151-162
    PubMedGoogle Scholar
  • 51 Johannesson M, Liljas B, Johansson P O. An experimental comparison of dichotomous choice contingent valuation questions and real purchase decisions.  Applied Economics. 1998;  30 (5) 643-647
    CrossrefPubMedGoogle Scholar
  • 52 Johannesson M. et al . Calibrating hypothetical WTP responses.  Journal of Risk Uncertainty. 1999;  18 (8) 21-32
    PubMedGoogle Scholar
  • 53 Blumenschein K. et al . Hypothetical versus real willingness to pay in the health care sector: results from a field experiment.  Journal of Health Economics. 2001;  20 (3) 441-457
    CrossrefPubMedGoogle Scholar
  • 54 Mitchell R C, Carson R C. An experiment in Determining Willingness to Pay for National Water Quality Improvements. in Draft Report to the US Environmental Protection Agency. Washington DC; 1981
    Google Scholar
  • 55 Smith R D. The discrete choice willingness-to-pay question format in health economics: should we adopt environmental guidelines?.  Medical Decision Making. 2000;  20 (2) 194-206
    CrossrefPubMedGoogle Scholar
  • 56 Ryan M, Scott D A, Donaldson C. Valuing health care using willingness to pay: a comparison of the payment card and dichotomous choice methods.  Journal of Health Economics. 2004;  23 237-258
    CrossrefPubMedGoogle Scholar
  • 57 Whynes D K, Wolstenholme J L, Frew E. Evidence of range bias in contingent valuation payment scales.  Health Economics. 2004;  13 183-190
    CrossrefPubMedGoogle Scholar
  • 58 Frew E J, Wolstenholme J L, Whynes D K. Comparing willingness-to-pay: bidding game format versus open-ended and payment scale formats.  Health Policy. 2004;  68 289-298
    CrossrefPubMedGoogle Scholar
  • 59 Frew E J. et al . Eliciting Willingness to Pay: Comparing Closed-Ended with Open-Ended and Payment Scale Formats.  Medical Decision Making. 2003;  23 150-159
    CrossrefPubMedGoogle Scholar
  • 60 Shiell A, Gold L. If the price is right: vagueness and values clarification in contingent valuation.  Health Economics. 2003;  12 909-919
    CrossrefPubMedGoogle Scholar
  • 61 Donaldson C, Thomas R, Torgerson D J. Validity of open-ended and payment scale approaches to eliciting willingness to pay.  Applied Economics. 1997;  29 (1) 79-84
    CrossrefPubMedGoogle Scholar

Prof. Dr. med. Gerold Stucki

Klinik und Poliklinik für Physikalische Medizin und Rehabilitation · Ludwig-Maximilians-Universität

Marchioninistraße 15

81377 München · Germany

Email: gerold.stucki@med.uni-muenchen.de