Empirical evidence pertaining to the influence of treatment preferences on attrition, adherence and outcomes in intervention evaluation trials is inconsistent. The inconsistency can be explained by the method used for allocating treatment and measuring preferences. The current methodological study is designed to address these factors by implementing the two-stage partially randomized or preference trial design, and administering a validated measure to assess participants’ preferences for the treatments under evaluation. It aims to compare attrition, adherence and outcomes for participants allocated randomly or by preference to treatment. The study is in its final stages of data collection; its protocol is presented in this paper.
Sidani, S., Fox, M., Streiner, D. L., Miranda, J., Fredericks, S., & Epstein, D. R. (2015). Examining the influence of treatment preferences on attrition, adherence and outcomes: A protocol for a two-stage partially randomized trial.