Exploring how individuals complete the choice tasks in a discrete choice experiment: an interview study

Area of Science:

• Health Economics
• Behavioral Science
• Decision Science

Background:

• Valid inferences from Discrete Choice Experiments (DCEs) require participants' active engagement and correct understanding.
• Assessing if participants understood information and employed complex decision strategies (continuity axiom) is crucial for DCE validity.

Purpose of the Study:

• To explore how participants evaluate and complete DCE tasks.
• To investigate participant understanding of DCE information and their use of complex decision strategies.

Main Methods:

• Structured interviews were conducted with 70 participants evaluating four DCE tasks aloud.
• Follow-up questions assessed understanding of information and application of the continuity axiom in decision-making.
• Rotavirus vaccination and prostate cancer screening DCEs served as case studies.

Main Results:

• Many participants could not recall exact risk attribute definitions.
• A majority preferred optimal risk attribute levels and mentioned at least three attributes (66%), aligning with the continuity axiom.
• Lower educated/literate participants mentioned fewer attributes and used attribute trading less frequently.

Conclusions:

• Most participants demonstrated understanding of DCE tasks, attributes, and levels, utilizing complex strategies.
• Participants are generally capable of completing DCEs adequately.
• Age, education, and health literacy necessitate tailored support to ensure comprehension and accurate DCE completion.