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

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 WTP_max 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 WTP_max 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.

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

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

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