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- Veldwijk, Jorien, et al.
(författare)
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Exploring how individuals complete the choice tasks in a discrete choice experiment : an interview study
- 2016
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Ingår i: BMC Medical Research Methodology. - : Springer Science and Business Media LLC. - 1471-2288. ; 16:45
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundTo be able to make valid inferences on stated preference data from a Discrete Choice Experiment (DCE) it is essential that researchers know if participants were actively involved, understood and interpreted the provided information correctly and whether they used complex decision strategies to make their choices and thereby acted in accordance with the continuity axiom.MethodsDuring structured interviews, we explored how 70 participants evaluated and completed four discrete choice tasks aloud. Hereafter, additional questions were asked to further explore if participants understood the information that was provided to them and whether they used complex decision strategies (continuity axiom) when making their choices. Two existing DCE questionnaires on rotavirus vaccination and prostate cancer-screening served as case studies.ResultsA large proportion of the participants was not able to repeat the exact definition of the risk attributes as explained to them in the introduction of the questionnaire. The majority of the participants preferred more optimal over less optimal risk attribute levels. Most participants (66 %) mentioned three or more attributes when motivating their decisions, thereby acting in accordance with the continuity axiom. However, 16 out of 70 participants continuously mentioned less than three attributes when motivating their decision. Lower educated and less literate participants tended to mention less than three attributes when motivating their decision and used trading off between attributes less often as a decision-making strategy.ConclusionThe majority of the participants seemed to have understood the provided information about the choice tasks, the attributes, and the levels. They used complex decision strategies (continuity axiom) and are therefore capable to adequately complete a DCE. However, based on the participants’ age, educational level and health literacy additional, actions should be undertaken to ensure that participants understand the choice tasks and complete the DCE as presumed.
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| 2. |
- Veldwijk, Jorien, et al.
(författare)
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How psychological distance of a study sample in discrete choice experiments affects preference measurement : a colorectal cancer screening case study
- 2019
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Ingår i: Patient Preference and Adherence. - : DOVE MEDICAL PRESS LTD. - 1177-889X. ; 13, s. 273-282
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of this study was to investigate to what extent the outcomes of a discrete choice experiment (DCE) differ based on respondents' psychological distance to the decision at hand. Methods: A DCE questionnaire regarding individuals' preferences for genetic screening for colorectal cancer (CRC) within the Dutch national CRC screening program was created. The DCE contained nine D-efficient designed choice tasks and was distributed among two populations that differ in their psychological distance to the decision at hand: 1) a representative sample of the Dutch general population aged 55-65 years, and 2) a sample of Dutch individuals who attended an information appointment regarding colonoscopies following the detection of blood in their stool sample in the CRC screening program. The DCE consisted of four attributes related to the decision whether to participate in genetic screening for CRC: 1) risk of being genetically predisposed, 2) risk of developing CRC, 3) frequency of follow-up colonoscopies, and 4) survival. Direct attribute ranking, dominant decision-making behavior, and relative importance scores (based on panel MIXL) were compared between the two populations. Attribute level estimates were compared with the Swait and Louviere test. Results: The proportion of respondents who both ranked survival as the most important attribute, and showed dominant decision-making behavior for this attribute, was significantly higher in the screened population compared to the general population. The relative importance scores of the attributes significantly differed between populations. Finally, the Swait and Louviere test also revealed significant differences in attribute level estimates in both the populations. Conclusion: The study outcomes differed between populations depending on their psychological distance to the decision. This study shows the importance of adequate sample selection; therefore, it is advocated to increase attention to study sample selection and reporting in DCE studies.
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