Veldwijk Jorien, Groothuis-Oudshoorn Catharina G M, Kihlbom Ulrik, Langenskiöld Sophie, Dekker Evelien, Kallenberg Frank G J, de Wit G Ardine, Lambooij Mattijs S
Erasmus School of Health Policy and Management, Erasmus University, Rotterdam, the Netherlands,
Centre for Research Ethics & Bioethics, Uppsala University, Uppsala, Sweden,
Patient Prefer Adherence. 2019 Feb 12;13:273-282. doi: 10.2147/PPA.S180994. eCollection 2019.
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.
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.
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.
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.
本研究旨在调查离散选择实验（DCE）的结果在多大程度上因受访者与手头决策的心理距离而异。
创建了一份关于荷兰国家结直肠癌（CRC）筛查计划中个体对CRC基因筛查偏好的DCE问卷。该DCE包含九个D效率设计的选择任务，并分发给两个与手头决策心理距离不同的人群：1）55至65岁荷兰普通人群的代表性样本，以及2）在CRC筛查计划中其粪便样本检测到血液后参加结肠镜检查信息预约的荷兰个体样本。DCE由与是否参与CRC基因筛查决策相关的四个属性组成：1）遗传易感性风险，2）患CRC的风险，3）后续结肠镜检查的频率，以及4）生存率。比较了两个人群之间的直接属性排名、主导决策行为和相对重要性得分（基于面板MIXL）。使用Swait和Louviere检验比较属性水平估计值。
与普通人群相比，在筛查人群中，将生存率列为最重要属性且对该属性表现出主导决策行为的受访者比例显著更高。两个人群之间属性的相对重要性得分存在显著差异。最后，Swait和Louviere检验也显示两个人群在属性水平估计方面存在显著差异。
研究结果因人群与决策的心理距离而异。本研究表明了适当样本选择的重要性；因此，主张在DCE研究中更多地关注研究样本的选择和报告。
