برچسب در مقابل آزمایش های بدون برچسب گسسته انتخاب در اقتصاد سلامت: برنامه برای غربالگری سرطان کولورکتال

Objectives Discrete choice experiments (DCEs) in health economics commonly present choice sets in an unlabeled form. Labeled choice sets are less abstract and may increase the validity of the results. We empirically compared the feasibility, respondents' trading behavior, and convergent validity between a labeled and an unlabeled DCE for colorectal cancer (CRC) screening programs in The Netherlands. Methods A labeled DCE version presented CRC screening test alternatives as “fecal occult blood test,” “sigmoidoscopy,” and “colonoscopy,” whereas the unlabeled DCE version presented them as “screening test A” and “screening test B.” Questionnaires were sent to participants and nonparticipants in CRC screening. Results Total response rate was 276 (39%) out of 712 and 1033 (46%) out of 2267 for unlabeled and labeled DCEs, respectively (P < 0.001). The labels played a significant role in individual choices; approximately 22% of subjects had dominant preferences for screening test labels. The convergent validity was modest to low (participants in CRC screening: r = 0.54; P = 0.01; nonparticipants: r = 0.17; P = 0.45) largely because of different preferences for screening frequency. Conclusion This study provides important insights in the feasibility and difference in results from labeled and unlabeled DCEs. The inclusion of labels appeared to play a significant role in individual choices but reduced the attention respondents give to the attributes. As a result, unlabeled DCEs may be more suitable to investigate trade-offs between attributes and for respondents who do not have familiarity with the alternative labels, whereas labeled DCEs may be more suitable to explain real-life choices such as uptake of cancer screening.

Estimates of public and patients’ preferences are of great importance in informing policy decision-making and improving adherence with public health-care interventions or programs [1]. Discrete choice experiments (DCEs) have become a commonly used technique in health economics to elicit preferences. The DCE is an attribute-based survey method for measuring benefits (utility) [2]. In a DCE, subjects are presented with a sequence of (hypothetical) scenarios (choice sets) and are asked to choose between two or more competing alternatives that vary along several characteristics or attributes of interest [2]. DCEs assume that subjects’ preferences (as summarized by their utility function) are revealed through their choices [2] (for further details, see Bliemer and Rose [3], Hensher et al. [4], Louviere et al. [5], and Ryan et al. [2]). A fundamental question that arises in the application of DCE is whether to present the choice sets in a labeled or unlabeled form. The unlabeled form involves assigning unlabeled alternatives in the choice set, such as “alternative A,” “alternative B,” and so on. The labeled form involves assigning labels that communicate information regarding the alternative. In marketing applications, labels tend to consist of brand names and logos, which consumers have learned to associate with different product characteristics and feelings. In the context of health economics, labels tend to consist of generic or brand-name medications, specific screening tests (e.g., colonoscopy, sigmoidoscopy), specific treatments (surgery vs. conservative), or other descriptors. An advantage of assigning labels is that alternatives will be more realistic and the choice task will be less abstract for the subject, which add to the validity of the results. Hence, the results may be better suitable to support decision-making at policy level. Nevertheless, by far, most commonly applied DCEs in health economics used unlabeled alternatives. The aim of our study was to empirically compare the feasibility, respondents’ trading behavior, and convergent validity between a labeled and an unlabeled DCE. All of these aspects were explored in the context of a DCE study directed at investigating population preferences for colorectal cancer (CRC) screening programs in The Netherlands. We were convinced that specific aspects of endoscopy (sigmoidoscopy, colonoscopy) or fecal occult blood test (FOBT) that determine its burden could not be totally captured by presenting an unlabeled “screening test A” variant to patients [6]. For that very reason, we expected differences between an unlabeled and a labeled DCE.

This study provides important insights in the feasibility and difference in results from labeled and unlabeled DCEs. The inclusion of labels appeared to play a significant role in individual choices but reduced the attention respondents give to the attributes. There was low convergent validity between both DCE variants largely because of different preferences for screening frequency. The choice for a labeled or unlabeled DCE may depend on the type of respondents and the research question. Unlabeled DCEs may be more suitable to investigate trade-offs between attributes and for respondents who do not have familiarity with the alternative labels, whereas labeled DCEs may be more suitable to explain real life choices such as uptake of cancer screening.