The Application of Preference Elicitation Methods in Clinical Trial Design to Quantify Trade-Offs: A Scoping Review

Background and Objective Patients can express preferences for different treatment options in a healthcare context, and these can be measured with quantitative preference elicitation methods. Objective Our objective was to conduct a scoping review to determine how preference elicitation methods have been used in the design of clinical trials. Methods We conducted a scoping review to identify primary research studies, involving any health condition, that used quantitative preference elicitation methods, including direct utility-based approaches, and stated preference studies, to value health trade-offs in the context of clinical trial design. Studies were identified by screening existing systematic and scoping reviews and with a primary literature search in MEDLINE from 2010 to the present. We extracted study characteristics and the application of preference elicitation methods to clinical trial design according to the SPIRIT checklist from primary studies and summarized the findings descriptively. Results We identified 18 eligible studies. The included studies applied patient preferences to five areas of clinical trial design: intervention selection (n = 1), designing N-of-1 trials (n = 1), outcome selection and weighting composite and ordinal outcomes (n = 12), sample size calculations (n = 2), and recruitment (n = 2). Using preference elicitation methods led to different decisions being made, such as using preference-weighted composite outcomes instead of equally weighted composite outcomes. Conclusion Preference elicitation methods are infrequently used to design clinical trials but may lead to changes throughout the trial that could affect the evidence generated. Future work should consider measurement challenges and explore stakeholder perceptions.