DCE attribute development investigating public policy for the provision of medicinal cannabis

Defining attributes and attribute levels for a discrete choice experiment (DCE) poses a significant challenge for practitioners exploring preferences for new or unfamiliar products due to the dearth of available information and limits in stakeholder knowledge. This study outlines a comprehensive process for identifying attributes and levels in a DCE aimed at gauging public preferences for health policies related to medicinal cannabis (MC).

A rigorous four-stage attribute development process was utilized and included i) the formulation of a preliminary attribute list from a scoping review and document analysis, ii) reduction of attributes via focus groups, iii) removal of inappropriate attributes using Delphi studies and research team knowledge, and iv) refinement of attribute language based on the feedback from think-aloud interviews.

A base attribute list formed from the scoping review and document analysis served as effective discussion stimuli in focus groups, especially for participants with limited subject knowledge. Structured focus group activities proved more effective than open-ended discussions in engaging naive participants. Delphi studies were found to be overcomplex for expert-led attribute prioritization. Think-aloud interviews during a pilot DCE were essential for assessing attribute language and clarity and understanding participants' decision-making processes.

The development of DCE attributes measuring preferences for an unfamiliar health product requires a multi-method approach. Evaluating the outcomes from various methods of attribute development yielded a refined list of attributes that were significant to stakeholders, allowed for meaningful trade-offs, and were presented in language accessible to the target population.